I recently tightened the RH tracks on my D4D s/n 83J. I thought they were mildly loose, probably 2" of slack using a straight edge. It has the hydraulic tensioning system, so I pumped in grease until there was 1 to 1.5" of slack using a straight edge (as per the manual). I ran it back and forth a few times and it seemed to keep that slack okay. I then used the dozer for some light earthmoving. After about 2 hours, I noticed the tracks were noisy. They had now become much more loose then before I tightened them. The rails were now slipping off the sprocket. Does this mean the hydraulic seals in the tensioner are bad? Since it loosened that fast? And worse then it was before?
The reason the tracks are falling off the sprockets is that the teeth are about 150% worn, foobarbed in other words. TBH it's a wonder it will move at all. If the sprocket teeth are in that condition what do the track links and bushes look like.? Also judging by the condition of the pin bosses on the track links the track rollers are also either worn out or close to it. All that is in addition to whatever problem you might have with the tensioner.
X2. The track adjusters may be the only good thing left on the frame,just over extended which causes them to leak.
Okay. Thanks for the replies. I didn't know the tensioner would leak if it was overextended.
I have a small amount of experience changing undercarriage on a dozer. But, the only sprocket replacement I've done is with the segmented, bolt-on sprockets. What is the method of installation for these single-piece sprockets like the D4D? Are they pressed- on?
Looks like you will be getting a fair bit more experience with this dozer . It looks like the track frames will have to come off . In that case cutting off the sprockets at the end of the spokes pretty much just where you can see them in your photo and replacing with a sprocket rim . There is a way to replace a rim without removing the track frame by cutting the rim in half with a fine grinder and re welding it .
That's a smart idea epirbalex
The attached is the Special Instruction for installing a welded replacement sprocket rim on a tractor such as the OP's. With a full Serial Number in addition to the 83J prefix I could probably dig up some more information. With the dirt shield in front of the sprocket installed it's hard to see whether the machine currently has a disc or spoked-type sprocket installed.
The full s/n is 83J-1634. That .pdf is very helpful. And the feedback about cutting the sprocket rim. Thanks, guys. I'm working on removing the dirt shields when I can fit it in.
Pulling the sprocket and following the guidelines Nige shared is certainly the proper way. It can sometimes be a slippery slope towards a complete final drive rebuild once you open that can of worms though. In my experience, if you are going the weld on in place route, rather than splitting the rim in half, cut out a wedge section just big enough to clear the frame. It is far easier to align the small piece to the larger section than two big halves. Be aware that usually the rim tends to spring inward a little once split, so you may have to make a plan to pull it outward a little to get the smaller section to fit correctly. Spend plenty of time getting your alignment correct even if it means cutting tacks loose and redoing multiple times. Remember to attatch your earth clamp to the sprocket and not elsewhere on the machine in order to save your final drive bearings.
Not mine though Tones , old guy who told me that has long gone . I like Glums idea of cutting out a small bit even if the rim pinches up a bit .
Interesting in the Cat procedure they only list 1/8" and 3/16" 7018 with no mention of 5/32". Not many refer to rod size in decimals. Not everyone can run 3/16" or has a welder with enough amps to run 3/16". I'm sure 5/32" could be substituted with out any issues. A 6010 root pass to get the deepest penetration was used when sprocket rims were welded on my track loader. Both pieces were beveled. 6010 root with 7018 fill/cap gives basically the same properties as if only 7018 was used. A root pass also helps to keep the hub and rim hot/warm prior to capping with 7018. I think on spoked rims you'd want to make sure not leave weld craters on the ends of the welds where cracks could form. Mostly if the pieces are preheated, and have sound (low hydrogen) welds and allowed to cool slowly shouldn't pose any problems. Not a job for someone who doesn't have adequate welding skills though. I can't imagine what damage would occur if the welds failed catastrophically.