Hey guys, I have a 1983 Cat D4E with powershift trans not moving. I was pushing a small amount of dirt and it just stopped, not loud noises or anything. You can feel the gears shift but no movement or binding on the motor. Just looking to know where to start, anyone have any common problems or suggestions? Thanks
Seems you'd have to break a bevel gear pinion shaft or lose the pinion shaft splines to kill power to both finals. Problem with steering clutch booster control might be a suspect but again not likely both sides would go at once. Does the same thing happen if forward and reverse? Could also be a problem with transmission control. Speed clutches engage before direction clutch If I remember correctly.
More thoughts... As transmission oil pressure drops when it gets to about 100psi or so the priority valve will shift the transmission to neutral (direction clutches don't engage) and remaining pressure goes to the steering clutch and/or brake booster system. Should be seeing a corresponding increase in transmission oil temperature as pump pressure/flow declines. First order checks would be transmission suction screen and filter then next would be pressure checks on the transmission pump and controls. If no other leaks are found but the pump is not up to spec and replacement doesn't solve the problem then suspect a worn torque converter.
Thanks Old Magnet, I will get to checking that out and let y'all know. I need to tow it up to the shop so I can get started. I tried it this am just to see if it changed over night and it has a slight clutch burning smell while it's running. I shut it down pretty quick. It smelled some lastnight and was still there this am.
check and see if your brakes are hung up. Bob
If brakes were locked up or dragging the engine would load up but apparently that is not happening.
Update... I pulled the floor plate tonight and it appears to have sheared the flexible coupling. The engine side spins freely with the motor.
Well that would explain the no go. I was going with transmission issue based on your info that the trans was still responding to shifting.
Sorry, I explained it wrong. When you shifted the gears you can still feel each one as it didn't feel like it was the linkage. Do the flexible coupling rubber give way after time and it as simple as replacing the bushings? Or is there anyway to know. Sorry I am new to this game and the cat field tech are very expensive. My dad is an old school diesel mechanic but not familiar with this machine.
Yes, those rubber donuts deteriorate in time. Would be a good idea to replace when you are in there. They are also quite sensitive to alignment. Good time to check that as well. How badly worn are the torque converter shaft splines? If they are worn bad a replacement is required or the new splined coupling will get torn up again.
It might take me a week or two to get it torn down. Right now as it seems it only sheared the rubber donuts. I'll have to get it pull down to check the rest. Thanks again.
OK, rubber donut failure is a fairly common and relatively easy to fix. Old age and misalignment are usually the cause. I was under the impression you had a failure at the splines. If it's just the donuts the splines are probably ok.
As OM says, your alignment needs to be correct or else you'll be replacing those couplings on a regular basis. Check for loose or broken rear engine mounting bolts and what shape the front vibration damper is in. Wish they had a u-joint coupler instead.
Here are the alignment check instructions. A must if you don't want to be in there again.