D2 Undercarriage - keeping an old tractor usable

I have a D2 that has been on the farm here since the early 1950s. The track chains/rails are quite worn, and the roller flanges are impacting the pin bushings.

I'd like to rectify this so that the machine will can remain useful and usable, although I doubt if i t will ever exceed 10 hours per year.

I have attached photos of the under carriage as is.

I'll double check the rail height, but I recall measuring at or below the max allowable wear of 0.25".

What is the easiest method of determining the roller wear? Is it possible to remove a rollers by slacking the tracks and jacking it up?

I've never seen pristine D2 drive sprockets, but I don't think these are to bad.They don't appear excessively pointed.



I'm currently searching for some usable track chain in the UK (in case anyone has any available). 


Thanks in advance.

Not to say you should not seek to get better running gear but by the shape of some undercarriages in Australia that is just run in so for a few hours a year it will probably last quite a while. We have built up rollers with welding in the past, quite a big job to get them out build up and grind off the high spots and refit.
Looks like you have some leaking seals don't run them dry that does not end well.

I replaced my rollers with D3 rollers, they are shorter so I made a spacer bar with 1 1/2 x 2 bar stock, drilled and tapped bar stock then welded bar stock to track frames. If you did the rollers you could get another 20 years out of that machine at the current rate.

These are on fleabay UK right now for 495 quid, rail height is like new and plates look nice https://www.ebay.com.au/itm/Caterpillar-D2-Tracks/254378337194

You can't rebuild tracks for that price, even if you could find the parts. New seals are needed, unless you want to keep the lube gun handy with some 00 grease, rebuilding those bottom rollers takes longer than you think it should, and costs more than you think it would.

I did my D2 5U a year ago, built up the rollers with weld, replaced the seals, fortunately the bearings were OK, because that adds a whole new dimension in challenges getting the old one's out, and getting new one's made, they are expensive.

[quote="D2Malvern" post=226710"]I have a D2 that has been on the farm here since the early 1950s. The track chains/rails are quite worn, and the roller flanges are impacting the pin bushings.

I'd like to rectify this so that the machine will can remain useful and usable, although I doubt if i t will ever exceed 10 hours per year.

I have attached photos of the under carriage as is.

I'll double check the rail height, but I recall measuring at or below the max allowable wear of 0.25".

What is the easiest method of determining the roller wear? Is it possible to remove a rollers by slacking the tracks and jacking it up?

I've never seen pristine D2 drive sprockets, but I don't think these are to bad.They don't appear excessively pointed.



I'm currently searching for some usable track chain in the UK (in case anyone has any available). 


Thanks in advance.[/quote]
Answering your questions:
- Easiest method for measuring wear is to use the undercarriage wear tool. The tool is specific to the model and there is one that suits all D2s. It enables you to gauge wear on the idlers, rollers, chain links (but not pins or bushes), and sprocket teeth. An alternative is to use calipers or similar to take measurements and compare them with the undercarriage wear charts.
- Yes, it is possible to remove rollers by slackening the track adjustment, jacking the track frame up so it's suspended and the track is hanging down, undoing the roller bolts, and jimmying the rollers out.

I just replaced a bad bottom roller on a D2. I slackened up the track chain and elevated each frame to get the sag you mention. I took a bar to check for any slop or issues with the ones that didn’t have obvious issues.
Your track chains will last quite awhile if you’re only planning on ten hours per year.
I am lucky to have a decent sized forklift and tools here; whatever you decide, don’t forget to be safe about it.
I wish to think the service manual will show you how to proceed with this exercise. Fun!

We recently replaced the rails on our 4U. Pads had to punched out to 1/2" bolts.  Berco rails and track bolts were about $2200.    Don

From the servicemens reference book From the servicemens reference book  [attachment=62520]20210316_124214.jpg[/attachment]

I love those old Service Book photo's, the Cat guy in the white lab coat is definitely the strongest guy on the planet, in the photo above he is holding a D2 roller with just 2 fingers! LOL

As you get older, those rollers gain about 5 pounds per year. It takes a little ingenuity to hold them up to get the bolts started.
I wonder if the while lab coats would be a hit in the ACMOC Store??  [img]/media/kunena/emoticons/hat.gif[/img]

Steve, I read something on the General Gear website that because the D3 rollers are 2" greater diameter than the D2 rollers, one would use a 1" thick bar to space the D3 rollers down from the track frame and that would keep the track geometry the same. What was your rationale for going to 1 1/2"? It would give you more meat for the new tapped threads but how does the tractor ride being 1/2" higher?