Hi There I am new to the forum and looking for some help. I have a d6c (47j272) powershift non turbo. I have completed many tasks on this dozer but I am having problems with the bevel gear flange on the left steering clutch side. Originally the dozer would not steer left, after stripping the clutch out I found that the hub seals had been chewed and spat out and the flange plate had four very nasty tracks all around where the hub sits in. I replaced the flange plate got new seals and put it back together. I got approx. 6days work out of her until the same again. I have now striped both clutches out and am in need of some help!!!!!!
You need to take it apart again and replace the bevel gear shaft bearings. Keep all the shims as you find them and you should be with in a shim or two of correct. The rolling torque for the bearing preload is 60 Lb" or about all you want to twist and get turning with your hand. If you keep the shims as they were backlash and preload should be right. The pinion is free floating so push it forward to check backlash. Later Bob
d6c Thanks bob, I did think about the bearings but they don't look bad. when the flange plates are bolted up there is no movement in the shaft. but I do agree this is the most likely cause as the scoring in the flange plate is consistent all round and about .5mm deep. The only other thing is that both of the duo cone seals have also gone and there does seem to be some play in the hub on the final drive side of the clutch case ! is this a problem or are these bearings not loaded ? thanks again jason
I'll let Bob answer all the technical stuff about your D6, but if you want the D&A procedure as well as the adjustment and testing drop me a PM. I'm not in the office right now but I will be in a day or so.
I assume by bevel gear flange that you are referring to the pinion flange and it's seals and bearings. What you describe is more typical of having pinion bearing problems where the pinion is not properly supported and through excentric motion, knocks out the seals and effects alignment with the steering clutches. Severe cases of these symptoms will do as you describe and I would suggest you look for failed bearings and wallowed out bearing holder as well as a wallowed out bore in the final drive case cover.
The final drive pinions have straight roller bearings and have a slight amount of end play. Bevel gear shaft is preloaded to 60 Lb" rolling torque the bevel pinion on Powershift trans are free floating and must be pushed forward to measure the backlash, check in 4 places Later Bob
Bob; just had bevel gear out of my D6D; book only calls for 30-45 inch/lbs. You have to rotate the shaft a good dozen times while doing this to make sure the rollers ride up onto there usual running seats to get the right amount of preload.. Also the right hand bearing set take all the thrust; you will probably find this is the bearing that's failed; but replace both bearings. Later D6Ds used a bigger capacity bearing on the thrust side because of this problem.
The original bearings were both the same, newer machines have one heavier bearing. Most older machines have been updated. Later Bob
thanks every one you have been a great help I think I will be posting other problems from the list here soon. she is testing me but I love the old girl. one last thing my machine is fitted with a cat winch and I am not sure (because of the pto shaft), that the bevel gear and pinion shaft can be removed? is it possible with the pto in the way or is it winch off time !!!!! thanks in advance jason
Me; id pull the winch; makes access to everything a lot easier. But it can be done. I know 20 yrs ago I pulled bevel gear out of a 69J D6c with a cat 56 winch still on it. But im abit fatter and slower now. pulled rippers off mine just to make access easier.
Did you wear all the paint off the winch getting the clutches out?