Help me diagnose a 4T65E problem
Posted: Sun Jul 29, 2012 9:13 pm
Having an issue with my home-rebuilt 1998 4T65E from about 4 years ago:
viewtopic.php?f=8&t=1483
Has no movement in any gear. Well, it'll go maybe 3 mph in any forward gear or in reverse (regardless how much throttle you give it), but that's it.
This just all of a sudden happened a few days ago while I was driving. Made no unusual clunk or noise when it happened, makes no unusual noises now. No CEL, but I don't have a tuner anymore (just a cheapy O'Reilly code reader) so it may have codes I can't see.
I think if it was a hard part (input shaft, diffy, drive/driven or chain) it wouldn't go at all (and I'd have heard something). I think if it was the torque converter, I'd have more go than I do have.
Drained fluid and dropped pan to see if the filter or seal had an issue; fluid looked fine, just a little clutch mud on the magnet, a few tiny flecks of metal in the filter. Filter fit into seal seemed a bit loose, so replaced seal and filter (now a nice tight fit). Did not fix problem.
Hooked up a 0-100psi gage I found in the garage to the pressure port; got:
P; 70psi
R; 70psi
N; 70psi
D; 55psi
3; 55psi
2; 55psi
1; >100psi
And none of these readings changed when goosing the throttle.
All the readings (except maybe 1st) are low in pressure. The book says they should be:
P, R, N; min 79-101, max 223-271
D, 3, 2; min 74-86, max 167-203
1; min 146-187, max 146-187
I don't think it's a stripped pump shaft, or I'd have probably no pressure and more shavings in the pan. I don't think it's the input piston seal, or I don't think I'd have so much pressure in first. Most signs point to a stuck open PCS (pressure control solenoid), but then wouldn't first gear be OK (it doesn't use the PCS as far as I know)?
Any other ideas? Next steps diagnostically?
viewtopic.php?f=8&t=1483
Has no movement in any gear. Well, it'll go maybe 3 mph in any forward gear or in reverse (regardless how much throttle you give it), but that's it.
This just all of a sudden happened a few days ago while I was driving. Made no unusual clunk or noise when it happened, makes no unusual noises now. No CEL, but I don't have a tuner anymore (just a cheapy O'Reilly code reader) so it may have codes I can't see.
I think if it was a hard part (input shaft, diffy, drive/driven or chain) it wouldn't go at all (and I'd have heard something). I think if it was the torque converter, I'd have more go than I do have.
Drained fluid and dropped pan to see if the filter or seal had an issue; fluid looked fine, just a little clutch mud on the magnet, a few tiny flecks of metal in the filter. Filter fit into seal seemed a bit loose, so replaced seal and filter (now a nice tight fit). Did not fix problem.
Hooked up a 0-100psi gage I found in the garage to the pressure port; got:
P; 70psi
R; 70psi
N; 70psi
D; 55psi
3; 55psi
2; 55psi
1; >100psi
And none of these readings changed when goosing the throttle.
All the readings (except maybe 1st) are low in pressure. The book says they should be:
P, R, N; min 79-101, max 223-271
D, 3, 2; min 74-86, max 167-203
1; min 146-187, max 146-187
I don't think it's a stripped pump shaft, or I'd have probably no pressure and more shavings in the pan. I don't think it's the input piston seal, or I don't think I'd have so much pressure in first. Most signs point to a stuck open PCS (pressure control solenoid), but then wouldn't first gear be OK (it doesn't use the PCS as far as I know)?
Any other ideas? Next steps diagnostically?