FYI anyone who comes across this, replacing solenoids solved my problem, so far. I had slip on 4-5 upshift, jolt on 5-6, and 2-1 downshift bump. Codes came up 4f8A and also 4f86 for 4-5 upshift but no other codes. Originally i just attempted with the bridge and finger seals, but that did not solve the problem. I have been able to test the car on at least one road trip and a few high load shifts, and so far so good. If anyone buys a car with a higher mileage ZF automatic transmission (over 120k miles, 200k km) at the first sign of transmission issues I would recommend this service.
how much air pressure do you use? I am building a TH350 and have positive, full piston travel with 25 psi, but I can hear very slight air passing past piston seals. in particular the piston on the front pump bench checked fully extends with air, but I can see it slowly bleed back down once I stop feeding it air , but still holding the air nozzle tight against the air feed hole in the pump. I read that this can be normal since the piston isnt actually pushing against any clutches.. Is this ok?
FYI anyone who comes across this, replacing solenoids solved my problem, so far. I had slip on 4-5 upshift, jolt on 5-6, and 2-1 downshift bump. Codes came up 4f8A and also 4f86 for 4-5 upshift but no other codes. Originally i just attempted with the bridge and finger seals, but that did not solve the problem. I have been able to test the car on at least one road trip and a few high load shifts, and so far so good. If anyone buys a car with a higher mileage ZF automatic transmission (over 120k miles, 200k km) at the first sign of transmission issues I would recommend this service.
when doing this are there any special precautions to take regarding pumping air in to these passageways?
how much air pressure do you use? I am building a TH350 and have positive, full piston travel with 25 psi, but I can hear very slight air passing past piston seals. in particular the piston on the front pump bench checked fully extends with air, but I can see it slowly bleed back down once I stop feeding it air , but still holding the air nozzle tight against the air feed hole in the pump. I read that this can be normal since the piston isnt actually pushing against any clutches.. Is this ok?