I bought a D6D dozer six months ago. I thought I had inspected it fairly well before I bought it, but it seems like the longer I own it, the more things I find that I overlooked. The other day I noticed the track frame alignment is off in the rear. The sprockets on both sides are sitting to the inside of the rails. Clearance between the sprocket and the rail was only like 1/8" on the inside and it appears that at times they are rubbing. So, what is the likely cause of this? I read that there are shims under the cap of the rear final that shim the track frame out, but how many shims are typically in there? Enough to make the sprocket alignment that far off? Does the track frame have to be pulled to remove shims? Or do I have some other more severe issue? The previous owner had been into the final drives at least once to "reseal" them, so they have been torn down in the past.
Check the position of the diagonal brace under the tractor (at rear) to see if shimming is possible. If the there is no room to the outboard side then you have other alignment issues that shimming won't cure.
Thanks Old Magnet. I wasn't real clear on my problem. The track frame actually needs to move inward towards the center of the machine. Looking underneath, it appears the diagonal brace can move inward approximately 1/2 to 5/8". From what I understand, removing shims allows the track frame to be moved further inward. If that is correct, how thick is the stack of shims that is typically installed? Is it thick enough that I will get close by removing shims? Or do I just need to tear into it and see what I have? Lastly, any idea on the size of the nut under the cap? I would like to get tools rounded up before tearing into it. Thanks for your time!
The shims are 0.036" thick, part number 2S4366 and start out with four per side. Sprocket should be centered between the rollers.