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D6 9U Trackframe Alignment Problem

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17 years 1 month ago #3856 by Dirt Dog
Some time back I noticed was that the outer bearing support housing was sitting to far forward in the trackframe. So far that the bolt holes wouldn't line up and it had been welded to the frame.

I got it in a bind a few days ago and the welds broke, so I figured now was as good a time as any to look into fixing it right.

After measuring and scratching my head and asking some questions, figured out that the RH trackframe must have taken a hit at sometime and was angled out at the front, which had pushed the frame back at the rear, thus causing the housing to be forward in the frame. The frame was also bent up at the rear behind the housing cutout.

I hooked a 1 1/2 ton chain hoist to the belly hook and the front of the trackframe right behind the idler and started pulling. Things started to line back up right away.

I took the one remaining bolt out and separated the bearing housing from the track frame and found the rear pin still in place.

After digging dirt and cement out of everything I found the front pin wasn't broken, it just wasn't there. Same with one front bolt.

I cut part way through the small part of the frame so I could bend it down at the back end to line things back up. Got it straight then welded the cut back together. Also welded crack at the front of the "dip" and on the inside.

I measured the existing pin and the holes. It measures 1.035 - 1.040 dia. so I am fabbing a pin for it. Inside front bolt hole is wallered out oversize, so I'm looking at drilling it out and retapping oversize.

2 broken bolts to get out also.

I think this is going to correct my alignment problem. As the repaired frame is now the pin/hole centers in the frame and in the bearing support measure the same.

Question: I used a big bar to bend the back of the frame down by hooking it into the sprocket. I noticed when pulling down that there is some up movement of the sprocket. Would that be the bearings needing tightening up? There is no movement in the dead shaft.

Here are some pics..

1958 D6 9U 27839 ~ 1944 JD BO Lindeman Crawler SN 333969

My favorite 2 toys are pullin' tractors and pushin' tractors. :cool:

My pullin' site
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17 years 1 month ago #3865 by Old Magnet
Hi Dirt Dog,
Wow, looks like King of Obsolete's project all over again:)
There should be no movement of the sprocket so a bearing tightening is in order.
That kind of impact/damage can raise hell with the bearings, bend dead shafts, and cause severe wear to the big bronze track frame carrier bushing and the swing arm bearings, especially if it has been that way for some time. All these items should be checked. Also keep an eye on the swing arm location on the dead axle so that it doesn't wind up jammed up against the casing or the retaining nut. KoO had to split the swing arm to recover his.

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17 years 1 month ago #3870 by Dirt Dog
OM, thanks for the quick reply.

I don't think this one will stack up next to all King did to the "hood", besides it is not near cold enough here....:p

I will try tightening the bearings, I hope that corrects the loose sprocket, and I also hope that may be part of the reason that I have had a final leak inside the sprocket.

After I get it lined up, back together and bolted down, I will check the swing arm location and measure the track frames relation to the tractor frame at the front again and see where I am at so far as alignment. Before I started the track pads were 4" wider at the front than they were at the back.

There is some slack between the big bronze bushing and the drum it runs against. I think the manual says max of .025 feeler guage between them. I'm pretty sure its more than that, haven't measured it yet. How critical is this?

Thanks for your help, I don't know what we would do without being able to ask guys like yourself for advice. :)

1958 D6 9U 27839 ~ 1944 JD BO Lindeman Crawler SN 333969

My favorite 2 toys are pullin' tractors and pushin' tractors. :cool:

My pullin' site

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17 years 1 month ago #3871 by Old Magnet
Cat doesn't make a lot of mention on this bearing or the swing arm bushings other than saying to replace if worn. On dozers the outer bearings are usually pretty well worn and severely worn when there are problems like you mention. Being that the specs start out at .0065 in. - .0095 in. and the allowable wear is .025 max. I would think yours is a good candidate for replacement. I would say both inner and outer bearings are critical to keeping the track frame from flopping around and giving the rest of the undercarriage a reasonable alignment.

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17 years 1 month ago #3873 by King of Obsolete
hey you got some nice stuff to work with there, i had one hole that was any good, LOL
you can drill them out to a 3/4 bolt if you like plus cut holes in the side of the track frame so you can get a wrench on the nut. asl for slop, don't worry to much a bout it, if you can still see the grease groove in the bronze bushing you should be good. you can always press it out and turn it a 1/2 turn because they only wear on one side. i would not want to buy that bronze bushing, you will need a good VISA, LOL
also you will have slop in the track frame arm down by the draw bar, take the slop out of there and the track frame will run straight in stead of pigeon toed.
on the the hub covered in grease you might be missing a dowel pin, this is not good because some thing was loose to cause the dowel pin to disappear.
pop this off and check it out, plus look real close at the roller bearing in side, it might be pitted. also see how much slop is in the 1/2 moon key, i ended up brassing my up to get thing tight again after 50 years of hard work.

thansk

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17 years 1 month ago #3875 by Dirt Dog

on the the hub covered in grease you might be missing a dowel pin, this is not good because some thing was loose to cause the dowel pin to disappear.
thansk


That pin is broke off, part still in the hub. I will see about looking closer at the things you mentioned.

Thanks dd

1958 D6 9U 27839 ~ 1944 JD BO Lindeman Crawler SN 333969

My favorite 2 toys are pullin' tractors and pushin' tractors. :cool:

My pullin' site

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17 years 1 month ago #3877 by King of Obsolete
ok, i drilled mine out to fit a 1" bolt (it was a long bolt with the threads cut off) the head will keep from falling through.
did you check under the bearing housing yet????



thansk

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17 years 1 month ago #3893 by Dirt Dog

did you check under the bearing housing yet????
thansk


I haven't got the adjusting nut to move yet.....:(

I have the lock out of it and the clamp bolt loosened off, have a 3 ft long pry bar hooked in one of the nut teeth, with a 5 ft pipe on the end of it levering against the track frame and it hasn't moved yet.

The track frame and bearing housing are separated right now, so as I pry on it I am picking the tractor up and mashing the trackframe down. I am going to get the broken bolts out (got one already) and bolt everything back together so there won't be any give, then I will pry on it again. I sure hope tightening the bearing will take the up/down play out of the sprocket.

What are the 2 little dowel pins in the end of the hub for?

Thanks dd

1958 D6 9U 27839 ~ 1944 JD BO Lindeman Crawler SN 333969

My favorite 2 toys are pullin' tractors and pushin' tractors. :cool:

My pullin' site

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17 years 1 month ago #3901 by Old 3T lover
Poor mans track alignment:

Swap sides with bronze outer bushing housings, Left to Right, Right to Left.

Take steel bushings out of diagonal trackframe brace and rotate back bushing to front, front to back.

If wear in diagonal brace bushings is excessive, Put 'best' bushing in the front and 'worst' bushing in rear with apropiate size shim stock under the rear cap bushing and bolt back to track frame, then remove cap and Grind the over hanging excess off and put it Back on. Track frames should line up then.

Yes, I've done this before. Ducks and runs for cover before the stuff starts flying.

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17 years 1 month ago #3903 by Old Magnet
The two little dowel pins on the end anchor the lock that holds the shaft end nut.

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