Well today I crawled stem to stern under the D8H 36A The undercarriage looks good except for one bad bottom roller. No2 on the right side from the front is frozen... looks like it has been for some time before I bought it. It has flat spots. Looks like its not even touching the rails while sitting level. Questions are this. How bad would it be to leave it alone?.. will it wreck my rails?.This tractor has no blade and will not be used for anything but joyrides and maybe some winching. Someday a show or two. If I do change it, I would assume I should get a used roller to try and match the others somewhat? Or will a new one work. Now I have changed all the bottom rollers on a JD 450C last winter while leaving the track on it.... But this big machine is another whole issue.I do not have a shop equipped for anything near this size. 3/4 drive socket set, 1/2 impact... etc I have, and I do have a cutting torch , welder, etc. I can get big jacks if needed, All I have are two eight tonners now. Anyone have an "easy way" to get a bottom roller out and in from underneath on this big a tractor?? I hate the idea of having to break the track. I assume that I would need to get it up pretty high on that side to get enough room to drop the roller out. Whats best?, heat the "roller boss" to pull the bolts?. Maybe they used some "never seize". On my JD, I did not have one broken bolt or even a tough one to get out. Rock rails same thing, all came out. This D8, who knows?... so far on the things I have worked on, nothing has been frozen up too bad. Any help from you "Big Cat" experts would be great. Thanks, Tim.
They can be changed without breaking the track. It does make it more challenging without a blade to help lift it. A good used one will be fine. Trying to match wear isn't necessary, especially on something like that. 9 out of 10 times a 1 inch impact or a good torque multiplier will break the bolts loose. Might start spraying some good penetrating oil in there to help loosen things up. If you've got some good oak blocks and a 20-30 ton bottle jack you might be able to lift the front enough to get the clearance needed to get the roller out. Let the tension off the track, may need to shove the idler all the way in to get all the slack you can. Break bolts loose, wrestle old out and new in. Easy peasy. May have to block, pull or pry track to get the slack where you need it to remove roller. No different than your smaller machine. Just bigger and heavier.
Either way you need something there turning . Depending who the roller is built by it maybe able to be refilled and loosened up . There could be a large allen key plug , worth a crack if the flats are not to bad .
Got a new one coming... cheaper to buy a new one from the local JD dealer thats close than getting a used one... No shipping charges involved and better price than I can get on Ebay. I think if i'm lucky I can change it here... A guy on ACMOC advised dig a 6 foot long hole, drive it over and slack the track. Jack or push it down and away you go.... I have a mini-ex so not a problem. I hope the bolts were zinc'ed up. Spring time project I think though.
Anything is better than breaking the bolts off, if they won't budge heat the bar above the end caps with a rose bud, that is where the threads are. Those rollers are heavy, watch your fingers, I made a cradle for a forklift to raise them up. Good luck, anti seize makes all the difference, hopefully the last guy used it, you would be surprised how many don't.
Me too Pete... I have a torch and a loader w forks on my tractor.. I got a 20 ton jack now also... I should have as good a chance as any to get it out. I will NOT break off more than ONE of those bolts, thats for sure. I would rather leave it alone and cut the flanges off the roller than try to drill those bolts out. It would be one thing if I was using it to make a living, but for a toy, it will live a long time.