I can't find a tolerance listed for this dimension at all in the books. Side to side is close to accurate and front idlers are centered, but the clearance between the front idler support brackets and slide bars these brackets bear against is about 5/16" clearance which seems excessive. There are supposedly shims under the slide bars, but I'm not able to ascertain whether they are there or not. What kind of clearance do you guys normally see in this application? I would think it's supposed to be much tighter than what I'm seeing as the idler support bracket(s) oscillate, or "hunt" around the track frame a bit when the tractor is moving. Thanks,
You can shim those as tight as you're comfortable with. I like to set up a bit loose myself.................simply because too tight can jam them up with dirt that has nowhere to go which makes adjusting the tracks a bit more work. JMHO of course
Thanks. I've seen them with clearance in the past on all machines, but never this much. Strange that the pads don't appear to have a groove or wear pattern worn into them. That however may be covered by the support brackets and may reveal itself once tracks are broken to work in the area.
Been conversing with a respected friend who knows these tractors quite well. Though there is apparently no specification for clearance dimension(s) being hunted, I know there is wear and is customary to "build up" and machine for more correct clearances to be attained. As mentioned, what started this was I noticed the idler support brackets slightly "oscillating" on the track frame when the tractor was moved either forward, or in reverse. There are specifications for this allowance and I'm certain they are being exceeded. From the parts manual it appears there may have been engineering changes throughout the production run as some tractors had, and some may not have had the shims I question. This may explain why I couldn't see any shims? Regardless there is known wear to be addressed. I'll work the tractor this summer, bring it home in the fall and break into the undercarriage to make repairs, then blast and repaint the tractor complete. The sheet metal is all pretty straight so should be fairly easy in the grand scheme.
Talked to my son a bit yesterday on this tractor and he tells me the bottom wear bar looks to have been about 3/4" thick and about 1-3/4" wide. The top looks to be about the same in width but only about 3/8" thick. Conversing with another retired mechanic, he relatively confirms those dimensions are pretty close but cannot attest to "exact". My assumption would be these wear surfaces could be worn down and the idler brackets themselves are worn away to a degree also. I have some 4140 alloy steel strip and once I know the proper dimensions and either countersunk, or counterbored mounting hole spacing, will have new ones machined. At the same time I'll weld up the slide areas of the idler brackets with some hardfacing rod to surface grind to a somewhat correct dimension. Yet another friend who works at the Case Construction dealership is going to measure the clearance on a new dozer they have there. It should be close for a starting point I'd think.