Our Komatsu PC200-6 didn't track straight. The previous owner had the same problem when he bought it years ago. Every so often one track would stop moving and then pop. Since I have a track chain side rubbing problem, I figured now was a good time to take the final drives apart to have a look. One side looks okay. There was some silver paste on the magnetic case plugs. Not much elsewhere inside of the drive. The other drive was full of silver sludge and the center drive shaft gear end was all chewed up. The bearings on both planetary gear sets are bad. The thrust bearing case surface is heavily grooved. It is at the machinist getting welded and resurfaced now. I just received parts to rebuild the drives. The needle roller bearings did not come with an outer race. I can't seem to find a source for them. The komatsu parts book shows the gear and race as one part. What is standard practice? Press or cut the outer race way from the gears and press in a new one? Leave it and hope the new bearings and pins will tighten up the gears? Before I turn the whole job over to the machinists, I would like to have an idea of what I am trying to do. smile
Never try to match up new bearings with old races, especially needle roller bearings. You will need to remove the old outer race and find the numbers on it, or the precise dimensions, and replace it with a new one. They will be metric bearings, of course.
Thank you for the guidance. So the numbers are hidden on the outside of the race! I can't find numbers on any part of the visible parts of the bearings. And yes Komatsu is metric. I think I will call the heavy equipment mechanics and turn the rest of the repair part of the job over to them. Thank you again.
Needle bearing numbers are on the end on all I've ever seen. Joe H
I was expecting to find numbers on the bearings also. I have the komatsu parts book and order what I thought to be the complete bearing. Only thing that came was the rollers in a cage. Perhaps the thrust washers on the side of these bearings wore off the markings? Searching a few bearing manufacture websites e.g. SKS, they sell the rollers in cages and an inner race. I didn't find mention outer races. They are not in a set as would seem logical. Or maybe I was snooping in the wrong catalog.
Update to the gear/race problem. Komatsu only lists one part number for the two parts. I ordered from an aftermarket supplier and received three new gears with the races already. I am loosing Japanese quality for Chinese but it may outlast the rest of the excavator. Also, I have three gears having the races cut out by a heavy equipment repair shop. Perhaps, I can find races from a local bearing supply house. This approach is will be more costly.