Gday from Australia. I have a 1990 Komatsu D31-PL18 dozer and am having problems with the oil level in my steering clutches. Somehow the oil is transferring from the clutches to the transmission. I can have all the oil levels spot on and after working the machine about 5-6 hrs all the oil has drained from the clutches and gone up the exact amount on the trans dipstick. I am scratching my head as to what the problem could be? Any help would be much appreciated. Cheers
Hi. From what I understand, the bevel gear is lubricated by the transmission oil and the steering clutchs are a seperate oil. im guessing its a bearing and/or seal failure in your bevel gear. I would drain the oils and filters and look for shiny bits in the filters then go visit the bank manager.
Hi Cliffy thanks for the reply. On my particular model there is 3 seperate compartments/dipsticks for the clutches, trans and bevel gear. I’ve heard of scenarios where a seal fails and allows trans oil into dry clutches on certain dozers but can’t figure out what would be happening on mine. I recently just did a 2000hr service on machine and there wasn’t any metal in any of the filters or trans strainer. I figured if I just kept adding oil at some point surely the levels might equalise between the clutch and trans but doesn’t seem to be the case
It sounds like the carrier bearings are lose . Shown as part number 7 , seals are number 8 . You may not be able to access this site in Aus , setting a VPN for NZ will do it BEVEL GEAR AND SHAFT (FOR TRIMMING DOZER) D31P-18 S/N 40001-UP [d31p-18r] Komatsu 113-21-32110 Part catalog k-part.777parts.org I had a similar issue with a D47U , loss of steering on one side caused by a drifting crown wheel . I caught it early and was advised I could use the bearings again after stripping them out . Yours will need stripping down to replace the seals so doing the bearings won't be an issue . The part number 11 is what you use to set the bearings and the backlash for the crownwheel and pinion .
Hi mate thanks for the reply. How big of a job is it to do? I’m guessing you need to remove the final drives to be able to pull the bevel gear assembly out?
I don't think you have to take out the finales , its not a small job . There will be settings for the bearings and the backlash on the crown wheel and pinion you will need . Its best you acquire a workshop manual for the model number range for your dozer , I had a stab at the model number of 40001 up . Even so sometimes parts books show more how something is assembled .