9U Final Seals Project

[Joel59]

As you might know, I have begun undertaking the project of replacing the bellows seals in my D6 9U. This is my first dozer, and my first major repair project with it. The machine # is 9U5896. Old magnet, as well as some others have already helped me, so I wanted to start a new thread to show some pictures of my progress, and, or course, ask some more questions.

I got the tracks split last Thursday with some help from Old Magnet on making a track pin punch holder. Mine is very crude, but it did the job!

[Joel59]

After I got the tracks split, I had to pull the front idler. That was relatively easy. One problem that I did notice was that one of the four pin bolts that runs vertically through the bearing block is broken off. I'm not sure how big a deal that is, but it hasn't been a problem yet.

[Joel59]

Now, yesterday, I had the pleasure of working on my extremely-difficult-to-move manual track adjuster. By the way, I'm only working on the one side of the dozer for now. After a days worth of heating, hammering, turning, and swearing, I got the large bolt and nut off. I think I will take the bolt and nut to a machine shop and try to get the threads chased.

[Joel59]

Here are the pictures of the adjuster.

[Joel59]

So today I got to remove the track frame. Another all-day job. It was no problem getting the front of the track frame off the equalizer spring, but I broke off three of the four large bolts that hold the back in. I will have to figure those out later. I built a little 4x4 dolly with some heavy metal casters I had to move the track frame. That worked good.:)

[Joel59]

After getting the track frame out of the way, I pulled the bearings, and got to the rear sprocket. I am concerned because I did not need a puller to remove the sprocket. It pryed off with a bar quite easily. The teeth don't appear to be worn out? What do you think? Also the outer bellows seal was not the greatest but the inner one turned out to be nothingbut a tangled mess! Guess that's why it was leaking!

[Joel59]

Here are a few pictures of my sprocket hub.

[Joel59]

So, can anyone tell me what number seals I need to order? What else should I replace while I'm in here? Any other thoughts- especially regarding the sprocket and the way it fit/came off. Thanks a million.

[Old Magnet]

Hi Joel59,
Good to see you are making some progress:D :D
The broken bolt you are showing (1 of 4) is actually just the spring tension loading bolt for the guide plate.
There is one taper pin/nut in each arm, the one towards the middle that ties the arm to the shaft. Be sure to tighten this one a little before you go to loosening the nut. This makes sure you seat the taper so it won't spin when you remove the nut. Can really be fun to remove once they start spinning on you. Once the nut is removed along with the spring plate a good whack with a hammer will send them flying.

That's one of the worst destroyed bellows seals I have seen. Having the sprocket loose like that is not a good thing and although the splines are in fair shape I doubt if they would make spec for required fit. Dimension "A" needs to be 0.006 to 0.190 in. with a 35-40 ton press fit to meet spec. It is not a case of just running up the taper until tight.

Attached is the parts breakdown for your tractor (I think) as it was still in my files. You will need new bellows seals, either the original style or the upgraded rubber style replacement or go to the duo-cone replacements. Check with Cat or your local source for what is available. You will also need new seal washers for the seal wear plates (quan-4). The wear plates themselves can be flipped over if they are worn/grooved. Also get the special gasket cement for attaching the seal washers.

The adjuster bolt threads look pretty bad to me, at least in the picture. I wouldn't invest much in thread chasing as these bolt are available aftermarket and are not all that expensive. Make sure the threads are good in the adjuster nut.

[Old Magnet]

Hi Joel59,
Good to see you are making some progress:D :D
The broken bolt you are showing (1 of 4) is actually just the spring tension loading bolt for the guide plate.
There is one taper pin/nut in each arm, the one towards the middle that ties the arm to the shaft. Be sure to tighten this one a little before you go to loosening the nut. This makes sure you seat the taper so it won't spin when you remove the nut. Can really be fun to remove once they start spinning on you. Once the nut is removed along with the spring plate a good whack with a hammer will send them flying.

That's one of the worst destroyed bellows seals I have seen. Having the sprocket loose like that is not a good thing and although the splines are in fair shape I doubt if they would make spec for required fit. Dimension "A" needs to be 0.060 to 0.190 in. with a 35-40 ton press fit to meet spec. It is not a case of just running up the taper until tight.

Attached is the parts breakdown for your tractor (I think) as it was still in my files. You will need new bellows seals, either the original style or the upgraded rubber style replacement or go to the duo-cone replacements. Check with Cat or your local source for what is available. You will also need new seal washers for the seal wear plates (quan-4). The wear plates themselves can be flipped over if they are worn/grooved. Also get the special gasket cement for attaching the seal washers.

The adjuster bolt threads look pretty bad to me, at least in the picture. I wouldn't invest much in thread chasing as these bolt are available aftermarket and are not all that expensive. Make sure the threads are good in the adjuster nut.

[Joel59]

Old Magnet,
Thanks again. I have a couple more questions. Some may be dumb- who knows! :D

1. On ordering the seals- Do I ask for (2) 8M3992 seals as shown in your first picture, or (2) 3B5730 as shown in your third picture? Which seal is "best"? The duo cone or the original Cat part? (remember I am only working on the left side of dozer- for now)

2. On the adjuster bolt/nut- Do you have a link or name of a good place who carries that bolt? Also, if I remember right the threads were better in the nut than on the bolt. I would still feel better knowing that the threads are "like new" in the nut as well. Can a machine shop clean threads inside that nut? How do they do that? Or is a new nut the ticket?

Side note- my closest dealer is about 60 miles away. Mail order is easiest for me, but not mandatory. thanks again.

[Joel59]

Oh yeah, now I remember the other question.

On the sprocket fit- What should I do? What would you do? Run it? Look for replacement? Any suggestions?

[ccjersey]

Joel,
I would find a good used sprocket. You could probably get one with a worn out ring for very little and transfer your ring to it, but if you could find a good one to start with. it could save the welding. The male splines will be worn some so you will want a good sprocket hub to go with them.

The nut on the adjuster can be cleaned out if someone will take the time to chuck it in the lathe,(may need a fixture for security) but the threads are usually protected by being inside as opposed to the external threads on the adjuster that stick out as the adjustment is made on an old track, and are running up inside the guide and exposed to all the dirt. I would take the torch and heat it so it burns out all the old grease, scrape it a bit with a wire etc and try it as is. Make sure the grease fitting/port is clear before you put it back on.

The internal thread cutting is done with a boring bar on something that big. Same thing that will make a smooth bore will thread if the tool is moved a precise distance along the bore for each turn of the chuck.

[Joel59]

CCjersey,

The only problem is when I look at my splines on my sprocket they look good to me. How am I going to know that the used one that I find is going to be any better? You don't happen to have one do you? Or maybe you might have a lead on one? Thanks.

[Old Magnet]

Hi Joel,
I know things are getting confusing.....it probably will for awhile.

To do the duo-cone upgrade one 8M3992 is required for one side of the tractor.

To do the bellows seal replacement two bellows assy. are required for one side of the tractor.

Now I'm going to confuse you even more.......
I know the old style metal bellows seals are no longer available but if you were to show a Parts man what you have they would know the latest upgrades. So far as I know you could expect the following:
3B5730 will upgrade to a 5H426 (rubber type bellows)
The 1A4088 wear washer is still used and can be turned over and reused.
The 6B6020 gasket is now a 7F5015
The remaining required gaskets, seals, and grommets should come with the new seals.

The cement for the 7F5015 gasket is part # 5H2471

For me, I like the duo-cone seal arrangement that reflects current production.

On the sprocket/hub thing.....you could waste a lot of time...and money trying to match used parts with no guarantee of fit. To me the only way you could come out is to be able to drop the hub into a used sprocket and check to see if it looks like it will hold spec. under installed conditions.........or get a used hub and sprocket match that is a known fit. Again there is a reason for the controlled depth of the press fit as there is a limit to how much displacement the bellows seals or duo-cone can handle.

The adjuster bolt part # is a 1F9490 screw.
Try Regal, Costex or Heavyquip.....or do a parts search on MachineryTrader.

[Joel59]

OM,

So if I'm understanding you correctly, It's not the spline stripping out on the shaft/hub that's the problem. It is that the bellows/duo cone might not seal?

[Old Magnet]

Actually some of each....the press fit tapered spline requires full area contact to hold. If you ride up on the unworn section at the expense of loosing contact area the press fit will not hold and also effects the working range of the seal.

Also brings up another question. With the seals that bad I'm wondering if much of any lube was being retained in the final gears. Did you happen to notice how much gear back lash there is?? When you have a chance, pull the drain plug and check for metal particles or pieces.

[Joel59]

Is there a measurement for gear backlash? What exactly is it? I constantly was filling the finals. It was like- check the gas fill the finals. :)

[Old Magnet]

Backlash is the amount of slop (or no load transfer) between gears when you rock them back and forth (rotating)......usually checked by rocking the sprocket when still on and tight.
Can be measured when gears are exposed but normally done by feel and judgment in this case.
Good gears have barely precipitable backlash. They are pretty forgiving but there are limits and the check can be an indicator of more serious problems.

[Joel59]

There is some slop there when you rock the sprocket back and forth. Don't know how much, I have nothing to compare it to. Is that slop between the bevel gear and pinion? I'm starting to get this sick feeling inside! :mad:

[Old Magnet]

No, the slop you should be detecting is between the bull gear and the pinion.
When eying the sprocket teeth, what is your estimate of the movement? There should be some. Not something I routinely measure about 1/4 to 3/8 inch or so is what I'm thinking for a reading off the sprocket teeth and still be ok. Got one I can go check.
Don't panic yet:) :)
Is there anybody near you that might be able to lend some over site to what you are doing? Pretty hard to do it all via remote;)

[Joel59]

I'll check tonight. I'll get back to you this evening. No qualified 9U mechanics around here that I know of. Just me. Yeah right Ha Ha Ha! :D

[Old Magnet]

Also, as a next step, clean up the sprocket and hub splines and put the sprocket back on (without pressing) and measure where it comes out compared to that diagram I sent you. If it slips on beyond spec. then we know it's a no go. If it looks like it will make press and still stay in range it may be usable. The splines don't look terrible but I can see the wear step on the inner end of the hub.

[Joel59]

In the drawing you sent me, is the thing labeled nut the large nut that I uncranked pushing off the tapered bearing? So I would put the sprocket back on and then recrank the large round nut- then measure?

[Old Magnet]

That is correct:D

[Old Magnet]

Well, my thinking was way off on that one:rolleyes: :rolleyes: Went out and measured the back lash on the final gears of my well used parts D6 and for what I felt was good is actually 0.026 on one side and 0.028 in. on the other as measured at the tooth tip. Guess you'd have to get near 0.040 in. or so to get concerned. Don't recall seeing a spec for this.

[Joel59]

Wow you've got good eyes! I did some measurement.

On the sprocket hub- I left out the tabbed locking washer and used a feeler gauge to measure between the hub and nut. I get right in the ballpark of
.020.

On the backlash- Without doing any measurement (going by eyeball) it is less than 1/4 inch. It sounds like I need to do some closer investigation if you are getting .026 or .028. After dinner I will go back to the shop and push the sprocket all the way forward hold a feeler at the tip of the sprocket and then move it. I assume that's how you did it.

[Joel59]

Well I've got a whole lot more backlash than you. With my dial indicator at the top of the sprocket tooth I'm getting about .086 :eek:

[Old Magnet]

I don't follow your measurement procedure.
What we're looking for is the distance from the end of the splines to the face of the sprocket hub. You can use the nut to push on the sprocket but then you would have to back it off to measure. Doesn't matter if you use the lock tab or not. Is that what you are doing?

The spec range is the 0.060 to 0.190 in. so if you have 0.020 now your not within limits and pressing would only make it worse.

I measured the back lash with a magnetic base dial indicator set up.
Using a feeler gage and fixed reference will work also.

Sorry, in looking back I misquoted the 0.060 as a 0.006.

[ccjersey]

I have them.

Just junked a bevel gear housing and final drives that had a set of sprockets that was worn out on the teeth, but still in place and tight on the hubs as far as I can tell. Anyway, that set is gone, but there's others.

I could ship you some, but anything for a 9U should be available in your county :D Maybe

My idea on this is that if it ran while it was loose, it won't last if you press it back on. Replacing the sprocket might do it, but as OM says, a good hub AND sprocket would be a sure thing.

I'll help however I can.

[Old Magnet]

At 0.086 in. backlash I'd be looking for a set of final drive gears to go with the sprocket and hub. Just what CC threw away....maybe:D

This tractor has seen a hard life.....do you know any of its history??

[Joel59]

Ok, Old Magnet I was measuring the wrong thing. I was measuring the gap between the nut and sprocket. I will have to remeasure (correctly) tomorrow. I understand what I am supposed to measure now. Please don't yell at me- I'm new at this and anxious to learn! After all, this thing was built almost 30 years before I was born!

I am pretty concerned about this backlash issue now. I used a magnetic base and dial indicator also. Everytime I try to move the sprocket in a forward and backward direction (determining the "slop") I get between .070 and .090 - in other words about 5/64 of an inch.

CCJersey- do you still have bull gears and pinions! I may well take you up on some of these parts. Do you have any experience in checking this backlash issue?

[ccjersey]

Went for $.08 a pound (net to us $.04)

I have kept that chunk of 9U for 10-15 years and a brake band was the only thing that anyone ever got off it. The transmission that was attached had gotten full of water and locked the whole business up. It originally had a Hyster towing winch on the back, but I couldn't convince "the powers that be" to save that as well. Now I really wish I had it. :(

I have other parts 9U dozers if you can't find something locally.

[Macca]

G'day Guys,

Would you have some specs for the D4, and upgrade for bellow seals?

[edb]

Hi Joel,
to more accurately check the F/D back lash you will need to push the inner sprocket hubs' taper roller bearing up into it's cup fully and squarely to align the center line of the hub to the dead axle. This in turn will set the bull gear( as the big sprocket hub gear is known here in OZ) in it's correct relationship with the mating pinion, there by allowing the correct B/L to be measured.
With the hub hanging loosly down you will indeed measure a lot larger B/L.
You also should be able to remove what appears to be an extra drain plug in the rear face of the final drive housing and better inspect the gear teeth. The extra plug is due to the one case fitting both left and right sides of the machine.
Hope this helps.
Cheers,
Eddie B.

[Old Magnet]

Hi edb,
What would you consider a reasonable range of back lash to be??

Also can't seem to find a torque spec for the sprocket retainer nut (for the D6 or D5)
Maybe it's not critical....got any info?? Thanks

[edb]

Hi OM,
how long is a piece of string?
To answer your query we must take into account that the brake should be applied or the brake drum rigidly held so as to not get a false reading from turning the pinion and taking the free play of :-
(1) the clutch discs to the drum splines, inner and outer in the steer clutch.
(2) any possible slop in the splined joint of the pinion shaft and the pinion flange--brake drum bolts to this. Because the sprocket joint was loose whoever assembled this side F/D may not have pressed any of the joints, so we need to be careful here.
(3) that the sprocket hub and its taper roller bearing are fully seated as described by me in a post above.

As the sprocket is larger in dia. than the F/D bull gear we will measure a larger than actual dimension at the sprocket tooth than is actually at the gear teeth. All that aside I feel something in the order of 0.040"-0.080" at the sprocket would be around 0.020"-0.060" at the gear teeth.
I had always rattled the sprocket after assembling a F/D but never measured the clearance, but kind of knew it was ok as I had put in serviceable gears.
Naturally there is a difference between a F/D with a single reduction compared to one with intermediate pinions to give extra back lash just to confuse it further for me to state a reliable clearance.
I would suggest as the F/D is all but dismantled that the case be removed and the tooth condition be ascertained. By the junk in the pix I would expect a fair amount of wear from dirt, but for a hobby machine I feel it would not be too critical.

OM
your actual B/Lash measurements are the only sure comparison to go by here. I have done this sort of thing when we had dirt ingress problems with Mitsu excav and early 200 series excav. F/D's.
I think I have only confused things here with my ramblings but however any input to the discussion is to advantage to give a clearer overall picture.

Tension at the Dealer was the same as for outer bearing adjustment---using the 7F9306 heavy duty castleated nut spanner wrench we put on a 6 foot piece of pipe and had one person bouncing on the end of same until the nut was tight--this would have been in the order of 600-700 lbs feet. For a D7 or early D8 we would have 2 persons on the pipe.
As the sprocket is supposed to be pressed on the torque of the sprocket retaining nut is not so critical as the press fit keeps the sprocket on its hub.
Hope this helps.
Cheers,
Eddie B.

[edb]

Hi Team,
just got back from youngest Grandson's Kindergarden (pre-school) Nativity Play, was great to see all nationalities of kids having fun.

Any way just looked in my D7 17A (I think) Serv. Man. and it says to tighten the sprocket retaining nut as tight as possible with the 7F9306 adjustable wrench, so that tallies with what I posted above.
My D6 U series Serv. Man. does not mention refitting the nut at all!!!! after pressing the sprocket to 30 tons.
Cheers for now,
Eddie B.

[Joel59]

edb,

thanks for your expertise in this matter. It does help a lot. I was trying to remember the Mathematics classes that I took in high school and college. I was thinking there was a relationship between getting a bigger measurement at the top of the sprocket as there would be at the gears themselves. This is certainly a hobby machine and not a daily user. In the summer time it gets used maybe 3 to 5 hours per week. I am going to pull the final drive case and inspect the gears (with pictures) as soon as I can get to it. Maybe tonight.

Old Magnet,

I'm really thinking that I'm going to be looking for a sprocket and hub. I will check the correct measurements tonight. On the machine's history- The machine came from Rhode Island (I had it trucked here to western NY). It was used on a pig farm and was supposed to be a 1 owner machine believe it or not. The man was in his 80's and clearing out his machinery. It was supposed to have 4700 hours on it. I take all of that with a grain of salt so to speak. From what I have found with the machine, the owner took good care of the easy-to-do things like oil and filter, fuel filters and such. However he wasn't to good about maintaining important things like final seals and track adjuster bolts!

Keep those thoughts and ideas coming. Thanks everyone.

[Old Magnet]

Hi Joel,
Yes, might as well pull the case as it looks like you will need to anyway.
I would still get both the sprocket fit and back lash measurements anyway, just to see where your at......plus I'd like to have the information:D

edb,
Thanks for the info......way more science than I was utilizing for just a "rough and dirty" check. I'd still like to see tighter clearances the 1/16 in. as these gears are already subjected to heavy shock loading.

Odd that Cat would not specify a torque for the retainer nut, they seem to cover most everything else.

I rely heavily on the D6 37A/44A service manual for power transmission information applicable to the "U" model D6
It has a lot more information and detail than the "U" model service manual....including excellent coverage of the duo-cone finals seals. I also noticed that Cat kind off backed off on the requirement for the seal installation tools as they probably weren't getting used anyway.

[Joel59]

Old Magnet,

I'm planning out this "correct" measurement on the sprocket/hub. First off, a couple real "dumb" questions.

1. The splines inside the sprocket itself- That center part does not remove does it? It's splines/sprocket/sprocket teeth all in one right?

2. When referring to the hub, we are talking about the shaft that is still on the dozer with the other splines correct?

Now I understand what I need to measure- put sprocket back on dozer, tighten large round castled nut, remove nut, measure from face of sprocket to end of spline on dozer shaft or hub correct? I know you listed the specs. as .060 to .190, so don't I want the number to be closer to the smaller spec. .060? That would leave me more room to press it on further. Am I thinking of all this correctly? Should I just hold the feeler gauge against the sprocket until it's even with the end of the splines, or is there a more accurate way? Thanks for answering my "dumb" questions. :)

[Old Magnet]

Yes on the first two questions.
Yes on putting the sprocket back on and seating it with the retaining nut.
No on the spec interpretation.
The minimum protrusion spec is 0.060
The maximum protrusion spec is 0.190

Ideally you'd like to be in the middle leaving plenty of room to accommodate the 30 ton press fit. Problem is, who knows how much travel the press fit will produce. Maybe edb could comment on this.

In any event the closer you get to the 0.060 the less there is to work with.

The easiest tool for this measurement would be the depth probe of a dial caliper if you have one, reading from the face of the sprocket to the beginning of the splines.

On the back lash check, with the sprocket off (don't want the weight) you need to re-establish the axis as though the unit were assembled and the inner bearing (tractor side of bull gear) seated. Use the outer bearing cage holder (with the keyway) to support the hub and somehow provide pressure towards the tractor to seat the bearing. Then take your back lash measurements.

[Joel59]

I don't think I'll ever hit those measurements anyway, based on my "incorrect" measurement. If I had a gap (.020) in this case between the nut and sprocket when tightened, what good was the nut anyway? I'm guessing it's (sprocket and hub) pretty well worn and the nut was unable to do it's job (holding sprocket tight) due to the too-far-worn splines. We'll measure her up tonight and see.:confused:

[Old Magnet]

Would agree, if the nut won't even reach the sprocket and with lock in place even, and assuming it is not a thread problem than it's over and measuring is a waste of time. It's new hub and sprocket time. Still should do the backlash check.

Here is another part number for the adjuster screw (takes in more models)
7H4876

[edb]

Hi OM & Joel,
sorry I could not tell you how far the 30 tons will push the sprocket on from the seated position with worn components, but 0.060" sounds a good round figure, and 0.020" or so for good components.
I have closed my eyes at the clients request before today and have pressed on sprockets to see the measurement at 0.020"-0.040" of hub spline protruding from the sprocket. To my mind the over travel of the sprocket on the hub would work for the more flexible bellows seals only as the less working dimension change tolerant floating ring (duo-cone) seals get too overloaded on the case side and underloaded on the outer side.
The main problem with worn splines is the wear step (unworn splines) at end of the hub and sprocket do all the work if you do not relieve them--grind back.
Joel, you ask if the sprocket bore splines are all one piece, they are, if you can see a change in the wear--contact pattern-- on the splines chances are the hub is cracked in from the radius in the area where the bellows seal plates sit. On heavily worked D4's & 955's it was usual to see cracks--breaks-- here to the point of the hub bit each side of the sprocket proper being tight and the sprocket bit being stripped of splines to the hub--no drive.
I think the first thing to do is see if there is dirt wear to the teeth and bearings in the F/D before we get too deep into what if's and maybe's. With the junk in the F/D that Joel pictured I suspect there is trouble ahead for the pinion and its bearings also.
Good luck with it Joel.
Cheers,
Eddie B.

[Joel59]

Tonight's findings-

Last night when I was measuring wrong I could feel play between the hub and sprocket. Tonight when I slid the sprocket onto the hub I gave it a good shove in, and it certainly seated further/better on the spline. No more of that play that I saw and felt last night. So I took the measurement as indicated by Old Magnet. Distance between the sprocket face and end of splines is 0.125 (according to my depth caliper). I can see, on the sprocket hub, where some of the splines have been flattened down a bit- perhaps from a press fit? There is no play in the splines when shoved on hard by hand. By the way, I went to take pictures and the camera needs charged :mad:

On the back lash- I pulled the final drive cover. That went surprisingly smooth, and that thing isn't near as heavy as it looks! Once inside the cover, I did the normal visual inspection. All the teeth have good square edges, and the only nics in the teeth were a few minor ones on the face (looking directly at) the pinion gear. There was a small amount of filings in the bottom (about enough to cover the drain plug hole). The backlash on top of the bull gear itself is somewhere in the neighborhood of 0.073 to 0.083 everytime I check it. Everything appears to have been getting lube. After all I added gear lube to this thing constantly before using it. I got the buckets in the garage to prove it!

Nothing (obviously) is put back together yet so pictures will follow.

[Old Magnet]

Well, we're defiantly getting data:D :D
but signals seemed to be crossed:confused: :confused:
What happened to the situation you described where the sprocket retainer nut wouldn't reach the sprocket???
Also did you read the material on how to get more accurate backlash readings??

We now have a new issue of repeatability.
The new sprocket readings look good....to good...although that is without the press fit which will be included in the spec range.
I suspect the readings look good because the indexing of the sprocket to hub has rotated (unless you center punched or marked the original location before disassembly)
To verify this good news I'd ask that you repeat the process at least a couple more times with new indexing each time to see what you get. If it averages out pretty close it seems there is enough travel available to accomplish the press fit and still be in spec.

Anxious to see the pictures.

[ccjersey]

Hey OM and edb,
Do the hub (male) splines ever stick out past the face of the sprocket, or are they still recessed (minimum 0.06"?)even when the press has done it's job?

[Old Magnet]

The spec. is 0.060 in. min. with a 30, 35, 40 ton press, depending on which one you want to believe:D :D
Even though it's the same parts the press requirement increases as though there was a problem:rolleyes: :rolleyes:

That's with the hub splines recessed in the sprocket.

[edb]

Hi ccj,
as OM says idealy the splines on the hub shoulder are below the sprocket face by the spec. amount. However I have had to fit up hubs and sprockets with worn splines and finished up with the opposite undesirable hub shoulder protruding the sprocket face situation--all at the clients request and risk in writing.
Hope this clears it up a bit for you as it is confusing unless you have done the proceedure.
Hope this scan helps.
Cheers,
Eddie B.

[Joel59]

Ok, thanks to CCjeresey I now understand why our signals are crossed. My male splines (on the hub/shaft) are sticking out past the sprocket 0.125. Now I understand why I couldn't comprehend the specs. and the way they worked. I was backasswards. :eek:

[Joel59]

On the back lash- I did put the keyed hub back on and stuck it in as far as I could push. Everything seems quite stable, and the only movement I am feeling is the movement between the teeth on the pinion and bull gear which comes out in the neighborhood of 0.080. This is with my dial indicator set up at the top of the bull gear. Things don't look that bad in there to me, but what do I know? :D With my finger I can feel the face of each gear tooth and feel some wear, but I would assume that to be the case in a 60 year old dozer.

[Old Magnet]

I don't understand why all the confusion:confused: :confused: the picture supplied early on should make it clear enough as to spline/sprocket position.
Your sprocket and hub is shot so lets move on to the next challenge:)

From what you describe the gears seem pretty good although the back lash is a little high. For occasional and hobby use they will probably be fine but I'd still like to see the pictures. In particular I'd be looking for signs of an even wear pattern across the face of the teeth (no wiping/diagonal pattern).

We haven't approached the subject of bearing condition yet. Can you post some pictures of the bull gear inner bearing and race, plus the outer hub/axle units and the exposed pinion bearing and race.

[Joel59]

I apologize for not studying the drawing close enough. To get to the bullgear inner bearing and race I assume I have to unbolt the sprocket hub from the gear, correct? I will take pictures of the pinion bearing (that is still in the final cover), gear teeth, bearing/race on the end of the pinion shaft, and hopefully I can uncover the inner bullgear bearing and race. I'll get the pictures posted up at about 4:00. The camera is on charge. :p

[Old Magnet]

Not necessary to separate the hub and bull gear.....you can remove as an assembly or separate now as you will be doing so eventually anyway. Pictures of the outer hub support bearing and race also plus the pinion shaft.....Basically get pictures of all rolling or rolled on elements.

[Joel59]

Do the hub and bull gear pull right out now?

[Old Magnet]

Yes.
That is one of the options to remove the whole works. If you had originally removed the outer end retaining hardware and unbolted the case cover the entire assembly slides off the shaft for service.....bit awkward and heavy but allows you to take to a facility that can do the press work. Might want to consider this when it comes assembly time. Otherwise you will need to have someone press the sprocket in the field.

[Joel59]

Can these gears be turned by hand with the other side track still on and on the ground? Such as putting trans. in neutral and pulling steering clutch in? Or is everything just too heavy to rotate by hand?

[Old Magnet]

Tying back the steering clutch lever (make sure brake is off) on that side disconnects the drive so you can turn the gears. Normally wouldn't take much effort but I'm not sure where you are with the hub & bearing support. Without anything holding the hub in I would expect the hub and bull gear to come out of the inner race.

[Joel59]

Here are some pictures

[Joel59]

Here are some more

[Joel59]

and some more

[Joel59]

Bull gear inner bearing and race. Race has a bad spot on it, but looks like it's been that way a while.

[Old Magnet]

Just quickly looked them over, will study closer later this evening.
Gears and bearings in general look pretty good considering but have done there share of dirt grinding. The inner bull gear race & bearing will need replacing. Chips missing on the pinion (but not critical) are usually a result of the bull gear caulking due to loose bearings (outer hub support). May need more pictures of bearing races, end views of roller bearings don't supply any useful information.....later.

[Old Magnet]

OK, got a chance look things over more closely:

The #5 picture in your first batch comes through with a weird looking image of the pinion tooth about to mesh with the bull gear. Is something going on there or is it just the picture angle and reflection.

The pinion shaft race shows a fair amount of wear, don't see any damage but it's not great. I'm sure there is service life left and these would be replaced in pairs....meaning a big job to pull the steering clutches to access the pinion flange and the inside bearing and seal. Would like to see a picture of the outer race that is still in the cover.....from what I can see the rollers look ok.

I don't see any reason to prevent reuse of the gears.

As I mentioned the bull gear inner race and bearing need replacing.

Some of the bearings have been replaced before. The original Cat stuff was usually Timkin and sometimes Hyatt. I believe the Bower units are all aftermarket replacements.

Depending on what you find for replacement parts you might want to consider getting complete assembly with better gears, bearings and may even include good reusable bellows type seals. Otherwise you will have to acquire individual parts, new or good used.

Until you source replacements your kind of limited on what else you can do except replacing the bad race. This can be done by wrapping and clamping some sheet metal around the dead axle and a fabricated sheet metal washer up against the case and placing a heavy welding bead around the inside of the race (not a job for a Harbor Freight buzz box) let it cool then pop it out with a pry bar.

Enough for now:D

Anyone else viewing these posts please add you comments. I'm sure I missed something;) ;)

[Joel59]

Thanks Old Magnet, for your time and expertise. On the pinion gear, it's just a goofy picture. Don't know why it came out like that. I'm still waiting to hear back from CCjersey on prices of his parts. I had another guy from this site pm me and say he has hub and sprocket also. Looks like they want $136.00 for the bull gear inner race from heavyquip.:eek: That was one of the few part numbers (from my parts book) that I got it to take. In my second group of pictures (top ones on this page) is it the bearing race in picture 3 that you're a little skeptical about? I can't just replace it and the bearing that it seats into (picture 4 same group)?

[Old Magnet]

Yes, that's the pictures. You could change out what you see but you don't have access to the inner bearing and usually these bearings are equally worn and both sides are replaced at the same time. Do you have reason to be going in to the steering clutches at this time?

The problem with those internet numbers, like you can access at Heavyquip is they don't show interchanges and upgrades. You almost have to know what the latest numbers are to get anywhere. You'd have a better chance finding interchange numbers off some of those replacement bearings you have or get standard bearing vs Cat number interchange. For instance the bearing cup you are looking for (7B4956) interchanges to a Bower/BCA (672308). Once your in to the interchange number system then you can expand to other brands based on the interchange number.

The other problem I've found is that there are not many internet sources that will sell bearings directly. Seems these suppliers have the market sowed up and control the prices. Any one out there got a good internet sales source????

[Joel59]

Steering clutches work good. Knock on wood.:D

Here's my parts list as of now:

washer/gaskets: (2) 6B6020
bull gear inner race: 7B4956
bull gear inner bearing: 7B358 (can't find this # anywhere on the net)
castle nut retaining washer: 3F1960
bellows seal: (2) 3B5730 (5H426) or duo cone 8M3992
cement: 5H2471
Gasket: 7F5015
Huge screw: 1F9490
What else?

[Old Magnet]

Your 7B358 is a Bower/BCA 67388 cone
Guess you didn't see the upgrade number for the screw (ya gotta read this stuff) 1F9490 is also a 7H4876 (more current number)
I'll look over you list later, sunny here today, gotta get some stuff done.

[Old Magnet]

The 7F5015 (2) or 6B6020 (2) gaskets will depend on what type of bellow seals you may wind up with. Could be the bellows seals you get with a used hub and sprocket can be reused ( the wear surfaces are replaceable if the bellows units are in good shape). Don't know what the availability of the due-cone set up is.

I recommend that you change the outer pinion bearing assembly now while you have access and change out the inner one later when you have to do steering clutch work. The interchange for the 6B5164 assy. is a Bower BCA #MR1312EHL

You will have to remove the dowel pin retainer in the top of the case to remove the bearing. Do you have the D6 Servicemen's Reference Book that shows this procedure?

Your list looks ok otherwise but you need to go through the parts diagram and pick out the various gaskets and seals.

[Joel59]

Thanks Old Magnet. I think I will end up getting all the new bearings seals/gaskets as new parts from either Cat or Regal. It looks like Regal has most of what I am looking for or at least they carry it. Now when I speak with them will I ask for the specific Cat part number or the bearing numbers that you are supplying me with? I assume the Cat part #'s and only use the bearing numbers if I find a bearing supply house. I have to find the part number for the gasket for the big final drive housing gasket too. I do have the serviceman's reference book. I want to strike a deal with either CCjersey or antqcatparts from this website on the used hub/sprocket, but I haven't heard back from them. This weekend I am going to go to work cleaning the shop, cleaning the inside of the final cases, and pulling bearings.

[Old Magnet]

Yes, Regal will go by the Cat #.
Correct on the bearing supply house numbers.
Cat has been fairly competitive with bearing prices as they don't control that market......might compare.
Problem is a lot of these bearings are coming from China and some of the fringe brands are pretty bad.

The big case flange gasket is shown in the parts breakdown I posted....6B9590

The 6B9590 upgrades to a 8H2247

[Joel59]

Old Magnet- (or anyone else)

I'm having a really tough time removing the inner final drive bearing race. I know you mentioned welding a tab on the race and prying it out. I am really not confident in my welding skills (all I have is a Lincoln arc welder) so I rigged up some extensions on a 5 ton 3-jaw puller. My question is, is it ok to heat that area with torches to get the race moving, or do you think I will mess up the seat? Another possibility would be grinding a slot in the race with my dremel tool. Would this be ok? I may knick the race's seating area doing this? What do you think?

[Old Magnet]

Hi Joel,
Instructions were to weld a heavy bead all around the center of the bearing race after protecting the shaft and case. Not just welding on a tab.
Once the weld is left to cool the race will shrink and should easily pop out of the seat.
Your Lincoln welder should be fine for this........6011 at about 150-175amp with a 5/32 rod is what I use.

There are other techniques.....torch, grinder, air-arc etc. but the weld method works really well and has the minimum risk of buggering up the seat.

This is the tool that Cat listed for the job but I don't think anybody used it.

[Joel59]

Old Magnet,

I am finally getting ready to put this thing back together. I bought a used sprocket & hub with an up to spec. fit. I have the bearings coming today.

On the bull gear inner bearing cup and cone, what is the best way to put them in/on? For the cup, do I stick it in the freezer over night, and heat the case to "sweat" it in? How about for the bearing? Does the same thing go for the pinion bearings? Thanks. Joel

[ccjersey]

Using temperature difference wouldn't hurt, but mostly they just tap in/on with a soft drift. swap sides a lot and just tap it a little at a time so it doesn't bind on you. If they were especially tight, you could try the chilling and heating.

If they're loose with both parts at the same temperature, then you know you have problems ahead of time.

My .02

[Joel59]

Thanks, CCJersey.

That's what I'll try, seems like they came off kind of hard, but maybe I'm making it out to be harder than it will be. By the way, I wanted to get those parts from you, but it seemed like it would be too difficult on both of our ends. Maybe in the future. thanks again. Joel

[ccjersey]

Yes, Mine are out in the mud still. We're working through projects to be ready for spring, but haven't gotten to the 9U trackframe yet.

I'm amazed you had trouble finding something locally. I guess the scrap iron market is having that effect.

[SJ]

At the shop we had a cooker like a french fry cooker and it had oil in it and we,d heat the bearings in it and then install them after they got good and hot and they,d slip right on.

[Joel59]

SJ,

That sounds like a good setup for installing bearings. I'll carefully try to drive them on.

CC- I found the sprocket and hub at a dealer about 100 miles from here. I'm embarassed to say what I paid, as the sprocket needs to be rerimmed, and the dealer's customer relation skills were below nonexistant. He must know he has the 9u market cornered in our area!

[Joel59]

Once the bearings are in, I'm ready to put the final case back on. I have the large case gasket coming, but wasn't able to get the gasket between the final case and the tube extension (about a 13 1/4" round gasket). Should I just make a gasket here, or just go with some form-a-gasket? I assume I should make one in order to keep the same thickness of everything. Should I add some sealant to the new gaskets as well? Thanks.

[Old Magnet]

Can't believe you can't get that gasket. If that is the case I'd make one and use the "tried and true" #2 Permatex. Forget that silicone stuff, it has a way of migrating to where it doesn't belong.

[Joel59]

Does anyone have any torque specs. on the bull gear-to-hub nuts? Maybe you just tighten 'em real good and fold over the lock tabs?

[Old Magnet]

Final drive gear to hub retaining bolt torque...........210 - 250 ft. lbs.

Must be making progress on reassembly:) :)

[Joel59]

Thanks Old Magnet. Yes, progress is being made and Florin tractor is really getting to like me I think! :D

[Joel59]

I was just going to give anyone interested a couple pictures of my progress.

[SJ]

That blocking under just the drawbar isn,t the safest thing to do. At the dealer we always put one under each side under the trans. case just inside of the final drive flanges then it was solid and couldn,t tip off. Also the front we had a special stand made up to slip under the front rad. guard that went from side to side under the front guard for good support.Depending on what you were doing up front we had to alter the blocking for the job but the rear we always done as I mentioned.

[Old Magnet]

Hi SJ,
Maybe not as bad as it seems...still got the other side track frame on the ground plus the blocking under the slide bar and under the equalizer spring. Maybe I'm missing something.

Looks good Joel:) :)
Nothing like a little paint to brighten things up.
Happened to look at the price of a new (after market) hub and it had a tag of about $1200. Hope you didn't get in to yours for more than half that used, sprocket included.

[Joel59]

Old Magnet,

I gave $475 plus tax for a used hub, sprocket, and retaining nut. The sprocket does need to be rerimmed though.

I had some other pictures I was going to post of the sprocket press and puller I am making, but it says my attachments are at their maximum or something like that. Is there a way to fix that? Thanks for everything.

[Old Magnet]

Hi Joel,
I'd say you are doing OK on the prices:)

Open up the "user cp" at the top left of the BB.
Scroll all the way down to the bottom says "attachments"
You have to delete some before you can add some:rolleyes: :rolleyes:

[Joel59]

I've been checking around for a sprocket rim part #3H2643. Heavyquip lists one for $157 and change plus $90 for shipping. Grace Track Co. wants $217.50 plus $62 shipping. So I called my nearest Cat dealer (Cleveland Brothers) and they wanted like $330 for one. Grace track does say that they will getting Berco's in in 30-45 days for $125 each. Man, do prices vary. I guess it can really pay to shop around.:rolleyes:

Any idea what it will cost me to get it cut off and new one welded on? Doesn't seem like a job for a very "novice" welder like myself.

[Old Magnet]

Never did one against the clock but I wouldn't think it would be more than a couple hours worth. Try that Grace Track Co. for a quote.
Main challenge is alignment.

[steve n carol]

I believe I read where the KoO did this to the HOOD. I do remember seeing pics of his progress on his website. If he canadian this in -40c, I would think that you could do this too, especally in a controlled enviroment as your shop is.

He hasen't posted on his site lately, I am supposing Belle may be visiting...sl

[Joel59]

This is the press and the puller that I have been working on in my spare time. The press idea and setup is compliments of EAMassey over on the ACME site. His was much better I admit. I am by no means much of a fabricator/welder, I am just hoping they get the job done. They are not finished, and are a work in progress. I still need to accumulate an enerpac pump and ram. I have been watching ebay for them.

[Joel59]

I am expecting the bellows seals to arrive today. I got 2 of the original
3B5730 bellows seals and original 6B6020 gasket rings. I plan to reuse my large metal washers by flipping them over. I also have the correct CAT cement. Can someone explain the proper procedure for cementing and installing this type of bellows?

Right now I am at the point of having the extension tube in place, and will be ready to install the inner bellows then sprocket. Any guidance would be appreciated. Thanks. :)

[Old Magnet]

Topic was covered a short while ago:

http://www.acmoc.org/ACMOC_BB/showthread.php?t=2506

[Joel59]

Thanks Old Magnet. Only thing is that the attachment you sent to D6Rick is not showing up for me on that link you sent me. Do you still have it? Thanks again.

[Old Magnet]

Yes,
Not all the info will apply but should get you close.

[Joel59]

Let me see if I have this right.

1. Cement the new inner bellows to the spacer
2. Cement the new outer bellows to the retainer assy.
3. Cement both sides of the washer gaskets.

Is that correct? I'm cementing one side of each bellows and both sides of the fiber wear washers? Anything else? Thanks.

[Joel59]

In relooking at Old Magnet's instructions, I see I have some of that wrong. Do not cement the seal to the spacer. I guess I am only cementing the cork seal (that came with the bellows) to the actual bellows. Serviceman's reference also says to cement both sides of the fiber wear washer 7F5015.

[Joel59]

One last try here. I have read Old Magnet's attachment and my Serviceman's Reference book closely now. Correct me if I'm wrong.

1. Cement sprocket side face of inner and outer bellows cork gasket to the bellows assembly on the 3 degree 33' contour.
2. Do not cement the back side cork (on inner bellows) to the bellows assy.
3. Cement the back side cork (on inner bellows) to the spacer.
4. Do not cement the back side cork-outwardly facing the machine (on outer bellows) to the bellows assy.
5. Cement the back side cork-outwardly facing machine to the retainer assy.
6. Lube face of metal washer and contact cork of bellows. (what to use here?-- regular grease?)
Wow this is confusing, but I think I got it.

[Old Magnet]

I think you were closer the first time:)

Cement both sides of the 6B6026 gaskets (now 7F5015)

Outer seal is doweled and cemented to the adjusting nut 3F1959

Inner seal is doweled and cemented to the extension (spacer) 7B7275

Cement cork seal 6B330 to the 3B3383 (bellows seal)

Grease between 6B330 and the 1A4088 washer
I believe moly grease was recommended in the former posts

[Joel59]

I got it all back together, except for getting the track reconnected.:D Does anyone have part numbers for whatever I need for a master pin/bushing. It still has regular D6 9U chains/pins/bushings. Thanks.

[Old Magnet]

Is the master pin the taper plug retainer type?

[Joel59]

Honestly, Old Magnet, I don't know what type it is. It was welded in, so I just ground off the weld on both sides, heated it up and drove it out. It does seem to have a small dimple or hole in each side if that helps.

[Old Magnet]

If its sealed type track:
Bushing 2A3241
Pin 8M7456
Spacer 8M7455 (2)
Seal washers 8M7454 (4)

If its non-sealed
Bushing 2A3241
Pin 8M7456
Collar 4B5954 (2)

[Joel59]

Old Magnet,

As you know I am working on side #2. I pulled the whole final on that side, and am taking to my cousin who has sprocket pulling equipment, heavy presses, etc.

On the bull gear inner bearing and race. If you remember, I replaced those on the first side of the machine. I notice the inner race is again in bad shape on this #2 side. I can't see any visible damage/wear to the bearing itself, but the race again has damage marks in it. They look almost like metal is flaked off in streaks that go perpendicular to the race itself. I don't have pictures right now. I am just wondering what caused this same type of wear on both sides. Do you think its just the dirt and grime that got in there, or do you think the outer bearing wasn't tight enough? Maybe it was just old bearings (they are Bower however). I just don't want it to happen again. :D
Is it absolutely essential to change these out at this point? I'm, of course, looking to keep costs down. Thanks for your knowledge.

[Old Magnet]

Could be several things but I would suspect:
1. The race was not changed during a previous overhaul (Bower not original) and some one else may have tried to save a buck.
2. Same problem with adjustment that allows misalignment/binding of the bearing and race.

Would suggest changing both the bearing and race so that they are matched otherwise you run the risk of a recurring problem. Not likely dirt in there, usually that leaves a pitted or sand blasted looking surface.

Kind of the wrong hobby if your looking to save money;) ;)
Trips to the Cat store usually run $300 - $400 per lunch bag full.

Done right, it should last a very long time.

[OldNuc]

My experience is that it is a very small lunch bag also.:(

[ol Grump]

And quite often working on these old critters, take the bag of money AND a lunch when you go visit the dealer. Sometimes it takes a while to track some of the bits down but it generally goes better it you offer the parts guy some of your wife's home made cookies/ cake or pie :)

[Joel59]

Ok, Ok.... back to the credit card I go. :(