Hello everyone I have a D8H 62A powershift Caterpillar bulldozer with some issues I couldnt trouble shoot in time for the season but id like to ask for some advice on what may be wrong. The issues are,
it will not stay in gear
pops out under throttle and under load
will not pop into gear without a little bit of throttle
seems to have grinding gears sound and feedback when shifting into reverse uphill sometimes
loss of forward power once it warms up
slowly lose steering once it warms up
the clutch levers don't really give any feedback I took apart the clutch valve assembly and that seems to be clean and working fine
I replaced the transmission pump because the book said that might be an issue
When I got the dozer it barley had any steering, I ended up replacing the left clutch pack and brake band because it had signs of heat stress and fractures on the surface of the clutch pack I figured somebody had drove the dozer with heavy brakes on and ended up destroying that left side, I'm worried about any seals in the bevel gear clutch housing area it might've gotten really hot and melted the seals I think the clutch release piston may be damaged but the book doesn't have much information on that it doesn't even show how to take that out or disassemble it specifically, so I was hoping anybody could give me an idea about that as well.
once I reassembled dozer with the new clutch pack break band and the new transmission oil pump I was able to turn right with a lot of brake pressure but I wasn't able to turn left very much still, then I took apart the clutch valve assembly and replaced transmission pump and I was able to turn left and right with a lot of pressure on the brake pedals. I adjusted the brake calipers both sides and I didn't help
after the dozer warms up and I run it for 20 minutes I start to lose all ability to turn the dozer just seems to want to go straight If I do apply enough break to get it to start turning the dozer it stop.
then after I ran it 5 or 6 times after 30-40 minutes I started losing forward power and then all power, then after I let it sit for nine hours and cooldown it had power again and I was able to drive back and I ended up parking it for the winter
book says it could be pressure modulation relief valve, load piston/differential valve spool improperly adjusted or stuck open, priority valve stuck open, leakage within transmission air or leaks in line oil or pump failure, and torque converter failure
the bevel gears been replaced I replaced the transmission oil pump and checked for leaks transmission doesn't seem to be leaking although I do have a leak into a final that seems to be filling up constantly, I believe it's coming out of the bevel gear/clutch housing I'm not sure. someone prior to me definitely got into the transmission housing underneath the seat and I'm not sure what they did if they adjusted anything im a bit nervous to get into the transmission, not sure if I need to check into that yet I was hoping it was something simpler
it will not stay in gear
pops out under throttle and under load
will not pop into gear without a little bit of throttle
seems to have grinding gears sound and feedback when shifting into reverse uphill sometimes
loss of forward power once it warms up
slowly lose steering once it warms up
the clutch levers don't really give any feedback I took apart the clutch valve assembly and that seems to be clean and working fine
I replaced the transmission pump because the book said that might be an issue
When I got the dozer it barley had any steering, I ended up replacing the left clutch pack and brake band because it had signs of heat stress and fractures on the surface of the clutch pack I figured somebody had drove the dozer with heavy brakes on and ended up destroying that left side, I'm worried about any seals in the bevel gear clutch housing area it might've gotten really hot and melted the seals I think the clutch release piston may be damaged but the book doesn't have much information on that it doesn't even show how to take that out or disassemble it specifically, so I was hoping anybody could give me an idea about that as well.
once I reassembled dozer with the new clutch pack break band and the new transmission oil pump I was able to turn right with a lot of brake pressure but I wasn't able to turn left very much still, then I took apart the clutch valve assembly and replaced transmission pump and I was able to turn left and right with a lot of pressure on the brake pedals. I adjusted the brake calipers both sides and I didn't help
after the dozer warms up and I run it for 20 minutes I start to lose all ability to turn the dozer just seems to want to go straight If I do apply enough break to get it to start turning the dozer it stop.
then after I ran it 5 or 6 times after 30-40 minutes I started losing forward power and then all power, then after I let it sit for nine hours and cooldown it had power again and I was able to drive back and I ended up parking it for the winter
book says it could be pressure modulation relief valve, load piston/differential valve spool improperly adjusted or stuck open, priority valve stuck open, leakage within transmission air or leaks in line oil or pump failure, and torque converter failure
the bevel gears been replaced I replaced the transmission oil pump and checked for leaks transmission doesn't seem to be leaking although I do have a leak into a final that seems to be filling up constantly, I believe it's coming out of the bevel gear/clutch housing I'm not sure. someone prior to me definitely got into the transmission housing underneath the seat and I'm not sure what they did if they adjusted anything im a bit nervous to get into the transmission, not sure if I need to check into that yet I was hoping it was something simpler