Alright guys I think I figured this out: car was very, very, very low on trans fluid. Added 2 quarts, and now it seems to be shifting fine. AAMCO wouldn't be my first choice, either....especially on this type of transmission, but I checked and fortunately the previous owner who had the trans rebuilt did purchase a warranty, which it's still under. It still jumps a little more than I'm used to if I accelerate hard off the line, but the revving up at highway speeds is now gone as are the other random revs. I had a similar thing happen in my 68 XR7 right after I got it and I recalled that had low trans fluid as well....checked the H/O and damn thing was almost bone dry.
Rough Shifting on 84 Hurst/Olds
- Thread starter carsofchaos
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carsofchaos said:
Good news. Hopefully losing apply pressure on the clutch bands didn't glaze them. Is the 1-2 shift firm under hard acceleration like it should be?
Yes I would say the shifting is pretty firm on the 1-2. When I've got it in full auto (Drive or OD) it does jump a tiny bit more than I would expect but then again perhaps that's normal for this transmission.
carsofchaos said:
Sounds normal. The OZ was calibrated to shift quickly and firm at WOT. If the clutches were glazed from low fluid it would slip and slide. Not a cheap fix.
Sounds like the problem was remedied, but I had a similar problem. Fluid was up to level and good (just recently changed, old,/possibly original fluid was fine). Problem persisted after the fluid change and TCC solenoid replacement. I ended up unplugging the 4 pin electrical connector on the driver's side of the transmission, and it shifts properly like it never had an issue. Complete night and day difference. Haven't had any issues since, and it's been unplugged for almost a year. There must be something very finicky with the TCC/lockup system with these cars, I'd still like to know exactly what is going on since I would prefer everything to be fully functional and not just have something unplugged, but it works so well now.
I really hated driving the car previously due to the issues, it would get confused, shift points were all off/funky, it didn't want to go into 4th, and once it did and you let off the gas it would slam back into third as if there was a serious problem and was slipping. Now nothing. Just goes right through the gears and into 4th at 45MPH consistently, downshifts with no issues.
I really hated driving the car previously due to the issues, it would get confused, shift points were all off/funky, it didn't want to go into 4th, and once it did and you let off the gas it would slam back into third as if there was a serious problem and was slipping. Now nothing. Just goes right through the gears and into 4th at 45MPH consistently, downshifts with no issues.
Wow, that's weird sounding indeed! I actually haven't driven the car since my last post due to the ice & snow around here. Not to sound like a dumba**, but what was the 4 pin connector for that you unplugged? The lockup? I need to drive mine again when the weather gets better later in the week and do a few more tests.
Yes, short of looking at the service manual to be sure, I believe it was for the lockup. I had read on here somewhere that doing that would help if you were having similar issues. I figured it wouldn't hurt as I had already had the fluid changed to get to the TCC solenoid, and the next step would be an overhaul. The other theory was that the TV cable was the culprit, but the car is all original and never has had the engine out or had any major work/been apart, so I didn't see how that would be it and messing with the adjustment would just make things worse. I am by no means an expert, just learning along the way with a lot of things, mechanically though. I'm sure that if you search on here you'll find all the information you need on the subject and any caveats.
Same here definitely not an expert, I learn as I go....I had thought the TV cable as well but it doesn't look like it was ever messed with on my car, either. The is the most "modern" car I've had out of my classic cars so it's got a lot of things on it I'm not used to seeing!
If the trans has been overhauled the tv cable has been disconnected and could be misadjusted. Without the engine running, have a helper "mat" the throttle and see how much slack the tv cable has. It should be tight. If not it needs to be adjusted. That cable must be adjusted correctly to avoid a low pressure situation and slipping clutches that result from low pressure. I am worried you have stated that you have run it low on fluid. This could have resulted in burning or glazing the clutches/band.
I am very worried after you say ammco worked on it. You could be missing your OZ vb/gov combo. The 2004r is very sensitive and swapping either and not having a matched set usually causes big probs.
The electrical connector on the trans carries current to the lockup solenoid to lock the torque converter clutch when called upon. By unplugging it you might be able to diagnose a stuck lock up solenoid, but it doesn't sound like you have that by your description.
Let us know how you make out.
I am very worried after you say ammco worked on it. You could be missing your OZ vb/gov combo. The 2004r is very sensitive and swapping either and not having a matched set usually causes big probs.
The electrical connector on the trans carries current to the lockup solenoid to lock the torque converter clutch when called upon. By unplugging it you might be able to diagnose a stuck lock up solenoid, but it doesn't sound like you have that by your description.
Let us know how you make out.
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