View Full Version : blade interchange among D4?

01-02-2007, 09:38 PM
Could anyone tell me if a caterpillar, I believe it is a 4S, blade off of a D47u would bolt onto a D47j?

Old Magnet
01-03-2007, 12:57 AM
Hi Nick,
The general answer is yes but there are some hurdles.
Tractors 7J7319 to 5T6473 did not come with the tapping strips provided for mounting to the track roller frames. These would be installed by removing the front three track rollers and once bolted up need to be welded in place. I don't recall at the moment why the cut off going back beyond 7J7319 but I suspect they are the earlier style track frames.
Also if you want to run the #44 hydraulic package you would need the early style pump drive for the D4400 engine.

Now that I'm awake and had my coffee I need to amend the 7J7319 to 5T6473 info. This pertains to modifying the front guard only. The one that wraps around the back of the idler. This needs to be altered to a two piece version like later units.
The blade mounting can be done on all the D4 models.

01-03-2007, 02:04 AM
One other thing make sure your 7J is a wide machine 7J????W, In the U ser. the 6U was narrow 7U wide in the G,J,2T&5T reg ser. no. was narrow or standard and the wide had a W stamped at end of ser.no.

Old Magnet
01-03-2007, 09:33 AM
You are not limited to mounting blades on wide gauge tractors. They were available for both 44in and 60in gauge.

01-03-2007, 10:16 AM
OM thats smart oif you to figure that out on your own. But he says the blade is from 7U thats means its already wide, would take lots of work to adapt to standard gauge

Old Magnet
01-03-2007, 10:37 AM
If your so smart then how about coming up with the answer as to why the blade mounting cut off at serial # 7J7319 back.

The wide vs narrow application is just for general information as I'm sure others are monitoring this post.

01-03-2007, 11:19 AM
Im not smart at all I was just answering the mans question about HIS 4S-7U dozer blade fitting HIS 7J. And what ever mounting hole in any 4G,7J,2T&5T they would be for Le Tour, Kay Baldwin, Lap C. or B.E. unless put there in later yrs would not be for the Cat 4S dozer because Cat did not make a dozer till after the war. Prewar Cat depended soley on John Deere Kilifer for tillage equip. and Le T for construction equip. they would be for Le Tour, Kay Baldwin, Lap C. or B.E.
My guess is that Ser. no. came from reprint parts book yrs later where Cat made replacment trac frames for all the big hubs for mounting their dozer but i forget when the hub changed

Old Magnet
01-03-2007, 12:09 PM
I have a slightly different take. It appears that the bolting pattern (holes) were established long before Cat had a blade as you say but tractors 7J7319 to 5T6472 did not have the tapping strips in place and had to be added. I'm thinking that tractors prior to that did not have the mounting holes drilled. I still can't explain whether or not there is an interference problem with mounting the tapping strips on earlier tractors as I know I have seen older units with Cat blade mounted. What I don't know is what/if any modifications had to be made to get it mounted.

Can anybody comment on these mounting requirements?

01-03-2007, 10:11 PM
I just looked at the D4 books and from 4G1-4G9999,7J1-7J9999,2T1-2T9999 & 5T1-7411 they all show drilled and threaded hole for attachments along with plain no hole frames. I have a RD4 with factory istalled LeT dozer with overhead frame and hyster winch

01-03-2007, 10:24 PM
Both 6G210w and 6G264w have the holes drilled . leroy

Old Magnet
01-03-2007, 10:38 PM
You can't tell from the regular tractor parts book what's threaded or not and whether holes are actually provided.
The actual blade mounting parts books and the Installation and Operation Instructions manuals have the details I am referring to.

Old Magnet
01-03-2007, 10:58 PM
Hi Leroy,
Can you see any reason why the later blade couldn't be mounted to the 6G model? Maybe interference preventing installation of the tapping strips? Got to be some reason for the cut off.

01-03-2007, 11:32 PM
You are correct about not being able to tell if threaded but as for holes they are there and in the Gser. book it shows 3 diff swing frames early with hole for Le T cable blade then in middle no holes with last being drilled for Lap. C. hyd blade.
As for what you are showing is just Cats way to show you how to mount their new blade on tractor 10 earlier then when they made blades. and if you drill new hole you could mount any blade on any tractor as long as width was correct.
Those ser. no. 7J7319-5T6472 are wartime machine all would have been OD green and no brass or alum tagsor filler caps built for the war they have nothing to do with any changes made in parts

01-03-2007, 11:39 PM
The track frame on the 6G is same as 4G, 7J and 2T thru 2T8269

Old Magnet
01-03-2007, 11:46 PM
I suspect there is more to it then that. If it was just a requirement that holes be drilled Cat could have stated it in their installation instructions. They actually do tell you to drill the holes for the inner support plate for the 7J7319 to 5T6473 using the plate for a template. I guess we'll have to wait till somebody actually tries it or comes up with a response about having done it.

01-03-2007, 11:55 PM
After looking at the Milt. D4 parts book the consider everything from 7J6753 up thru 5T??? to be milt. and it shows only 1 swing frame for all with holes for the Lap. Ch. hyd blade.

Old Magnet
01-04-2007, 12:05 AM
I wonder if it boils down to an infringement issue between Cat and LaPlante Choate involving those earlier models.

No, that's not right it would more likely be infringement with LeTourneau

01-04-2007, 05:44 PM
Don't forget that some D4's (like mine) were sold by Cat with dozer manufactured by Bros. They are completely different than most. I don't think the Bros dozers would swap very easily.

01-04-2007, 06:52 PM
The Caterpillar Bulldozer Product Line brochure of the late 1940's, gives every detail you want to know about all the Cat blades .. except for precise model fitment.
For the 4S blade, it merely states "for D4 model" .. without listing any precise model or S/N range .. which information was often supplied with other attachments.

Accordingly, I don't believe there would be any major problems with fitting a 4S blade to a 7J D4 .. apart from some normal minor modifications, as with all 'swaps'.
The 7J, having the smaller outer sprocket hub bearing, will not have interference problems with the blade mountings on the track frame, as the 4S mountings are designed to accommodate the large diameter sprocket hub bearing.

A lot depends on what the 7J has been set up for, previously .. and even whether the trackframes are original. It's not unusual for a 60+ year old tractor to be wearing track frames that have come from another tractor of a different S/N range.

The booklet that would be of most use, would be the "Installation & Operation Instructions" for the 4S blade.
This booklet should outline blade fitment instructions for all D4's.

01-08-2007, 06:08 PM
Thank you everyone for the replies. I didn't anticipate this many answers; I thought it would be a yes or no. I still have to unload the trailer and get the 7j going as they are both recent purchases. I foresee some fabrication as the moron that pulled the blade started to cut one of the blade supports off with a torch instead of a wrench.

04-01-2017, 10:40 PM
Well I guess we will know soon. I have a 7j and just picked up a 7u with the 4S cat blade and 44 hydraulics package. Going to swap it all to the 7j and hopefully the belly pan as well. Looks like the radiator might fit as well. The top coolant mount appears to be smaller bolt pattern so might have to retro fit something. Any one know if I could just swap the top tank? The 7j has a full width core and the 7U has the 75/25 oil cooler/radiator core.