I have a friend that has a D68P Komatsu dozer that he overhauled the engine on because it has tore up a main bearing thrust washer. He thought that the Torque converter caused the problem. He had a rebuilder in TX overhaul the converter. He told me the rebuilder replace some bearings. He has a service manual and thought that he installed it correctly. He has around 50 hours on the dozer and the engine started to knock again. He checked his crankshaft endplay and it has way too much again. He ask if I could find out in the forum what in the torque converter may be causing this problem.
need to replace bearing bolt up convertor and check end play did he do that last time
He said he did. I was wondering if the rebuilder could have done something wrong?
If he had end play after he bolted convertor up then he must have a problem in the engine not convertor
The engine had .004 end play after rebuild until the rebuild torque converter was put on and run for 50 hrs. Now engine has .200 end play.
Do you know if it had end play after the torque was bolted up
Engine crank endplay was ok. I don't know if the torque converter was ok. There is nothing that can put side load stress on the crank thrust bearing and affect the crank bearing except the torque converter.
Does the convertor fit into a spline like coupling on the flywheel like on a cat if so I wonder if a washer or something got wedged in there when going together
Which all goes back to Dave's question regarding whether the crankshaft end float was checked AFTER the installation of the torque converter. From above it was 0.004" after the engine was rebuilt but no measurement that I can see about how much it was after installation of the converter, or even if it was checked at that time.
That end play sure sounds kind of tight on the rebuilt engine. The spec on a Komatsu 95 series engine is .005 to .012 inch and the repair spec is .015 inch. I don't know if this machine is using that engine but most engines I have worked on run in that range. The other thing that comes to mind is how did anyone get a dial indicator in that small space in front of the crankshaft in the front of the machine to check the current amount of end play? Anyway you look at, the only way to get to the current amount of end play is to push the crank either forward or backward into the thrust bearing. Have you pulled the oil filter and looked for damaged material? Maybe the engine was put together wrong?
Are we talking about a D68P with the Cummins N855C engine??? the only bearing that I know that can be fitted in the torque incorrectly is the thrust roller with the Vee mark on both sections, you put the 2 Vee's together for correct positioning, what side of the thrust bearing is taking the wear? no doubt to check the end float he is using the starter hole to get at the flywheel. tctractors
I just happened to be looking at the 6D125 motor manual and it lists the D68P-1. No idea if any other engine was used or if there are more than one version of the D68P (like the D65 series!)
The D65-7 had the Cummins NH220-CI fitted, the D65-8 Had the Komatsu 6D125-1 engine fitted, the D68-1 (E or P) had the Cummins N855C fitted, I hope this helps? tctractors
Do you know if they ran the same undercarriage?
Do yall know where I could find undercarriage for a 1990 d68p-1? Or if there are models that will interchange?