Previous thread from a few days ago about "D6c Steering Clutches Not Completely Releasing" got me wondering about my clutches, which act the same way. Looked up the specs for my s/n range and started checking pressures. ---------------------------------------- Pump pressure at "G" (trans filter) spec: 315 psi @ low idle, 350 ±10 @ high idle (in neutral) Checks: 300 @ low idle and 410 @ high idle ---------------------------------------- Pump pressure at "K" (steering chk valve) spec: 315 psi min @ low idle w/clutches released (I assume that means levers pulled out), (No High idle spec) Checks: 330 psi w/both levers in 225 psi w/both levers pulled 265 psi w/left lever pulled 265 psi w/right lever pulled --------------------------------------- LH Clutch pressure at "J" (pipe to LH clutch) Spec: 315 psi min @ low idle w/clutches released Checks: 0 psi w/levers in 220 psi w/both levers pulled 260 psi w/LH lever pulled --------------------------------------- RH Clutch pressure at "H" (pipe to RH clutch) Spec: 315 psi min @ low idle w/clutches released Checks: 0 psi w/levers in 200 psi w/both levers pulled 240 psi w/RH lever pulled --------------------------------------- Hope that isn't too confusing....maybe someone can tell me what could be causing the pressure variations. The pressure at the filter seems odd...too low at low idle & too high at high idle. Has someone boosted the pressure to compensate for a worn pump? Note: The seals at the steering clutch pistons have been replaced to try and help clutch dragging (mostly when cold), but it didn't improve it. I haven't checked any of the other trans pressures listed on the spec page yet....mostly concerned about clutch operation for now. Next time I'm up at Ziegler's I may see if there's someone in shop that's old enough to have some experience with a D6c. View attachment Scan_Doc0001.pdf View attachment Scan_Doc0002.pdf View attachment Scan_Doc0003.pdf View attachment Scan_Doc0004.pdf View attachment Scan_Doc0005.pdf
I don't like the 300 Low idle 400 High idle numbers. You have a worn pump or the seals blown off of the small tube feeding the trans valve at the RH rear corner of the trans. A good system should hold 90% of High idle (360) at low idle. Check the tube with engine running trans cover off. Then check the steering linkage adjustment, if it's off oil can leak and pressure drop. When you resealed the steering clutch pistons did you reseal the flanges too? Are the bevel gear bearings good? Linkage adjustment most likely problem Later Bob
Very possible pump is worn....Not sure which seals you're talking about on tube feeding trans valve. I did replace the check valve that sits on top of the steering clutch valves (location "K" from scanned pages) Seat & ball showed wear so I put in new. Pretty sure I replaced all seals in clutch assy.....Bevel gear bearings weren't "bad" but I replaced them while I had it apart. I'm sure I went through the linkage adjustment at the time, but probably should be rechecked. If the problem was just the pump that would be a simple, if not cheap, fix.
The sleeve is inside the trans case under the tube end that delivers the oil to the steering valve. The seals are the soft silicone yellow ones and wear down. Later Bob