Here’s a quick video about eliminating possible sources of the tranny troubles my ’76 TA has been having. The car has a not-factory tranny – a TH2004R, which is in the car because it has overdrive, a big helpful thing when you’ve got an old muscle car with 3.90 gears in the pumpkin. Without overdrive (a deep .067 ratio in the TH2004R) the engine would be spinning around 3,400 RPM at 65 or so. With it, the revs drop to just over 2,000 at the same road speed.
Anyhow, last week, the the tranny developed trouble. It wouldn’t shift into overdrive – and then it wouldn’t shift from second to third. I gimped it home in second – and since the, have been trying to suss out the trouble.
The first thing I checked – after dropping the pan and draining the fluid – and looking for things other than fluid in the pan – was the governor. This is a mechanical thing that looks kind of like a spinning top and works more or less the same. Weights mounted on a shaft expand outward in response to the speed of the spinning shaft. There is a small spring – a weak point – that sometimes breaks and causes the governor not to. Shifts don’t – or do, but not right.
So I took the governor out and inspected it; all kopacetic – so back in it went. The next thing to check – the subject of this video – is the throttle valve (TV) cable. This cable operates a lever inside the transmission, that depresses a plunger inside the valve body – the hydraulic control box of an automatic transmission. It is very important that the cable tension be adjusted properly, so I decided to make sure it was. It seemed to be. Check!
The next thing to check will be the torque converter lock-up sender and related parts. Assuming they check out, the plan is to button it all up, fill it with fresh ATF – pray to the Motor Gods – and see what happens.
If nothing good happens, I foresee a Hurst-shifted (by me) Super T10 in the TA’s future.
Maybe it’s a sign from the Motor Gods!
. . .
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Good luck on the fluid change.
FWIW tv out of adjustment or lockup not working should not cause the trans to be stuck in 2nd gear.
If it were a 4l60e I would suggest verifying shift solenoid operation…
I do recall if you strip the (plastic gear) teeth on the governor (th350) it will be stuck in 2nd gear. Still, yours was fine :/
Don’tcha just hate it when that happens? But the wife’s turned out to be bad fluid, not old, but had been fairly hot and over 30,000 miles, the maximum for “extreme driving” which is what every vehicle is doing in the heat of west Texas summer. We had 109 a month ago and 105 the same week along with a high of 51 right in there within a week or so. We’ve had many days in the upper 90’s and supposed to have 101 today. It feels like it’s going to get there if not higher. The day it was 109, the forecast was 104. If you don’t like west Texas weather, wait a while, it’ll change.
Anyway, on her car is was really screwing up and would go into 3rd but barely and with a shift that felt like everything was bout to give up. It also had leak on an o-ring on a line. Not enough to affect it but one of those things that drive me to distraction. I had a broken leg at the time so I had a place change the filter and install all the Amsoil(thought I had more, 3 gallon bottles lined up and I told the wife to bring it in the house since the temp had just dropped about 60 degrees. They were lined up in front of the heater. I reached down and found a full one, one with half a pint and the other empty. Oh joy, but I went on anyway thinking I could get another brand of synthetic and had a quart of Pennzoil synthetic. There wasn’t nearly enough fluid so I drove it home slowly and it shifted better but didn’t want to go into OD. Next day I go get several quarts of synthetic fluid and top it off. Then it drove semi-normally with crazy shifts and finally got into OD but no lock-up. Just kept driving it and it got better and better and finally shifter pretty normally and got into lockup. It continued to get better so I knew the transmission was getting cleaned, the great thing about synthetic any sort of fluid.
So it worked ok for the next 6+ years and then the door that had the entire guts replaced got to where it wouldn’t open and the passenger side would open if you held your mouth right and stood on one leg and blinked one eye a the right rate. Then it began leaking engine oil at the top of the intake gasket so we drove it so seldomly and the battery died and that, as they say, was that.
I hope yours will heal itself(try standing over it saying “HEAL” several times. It can’t hurt and you might have a revelation of your own. Anyway, good luck with it.
And since it’s not my car I hesitate to give advice on a manual but the Tremec 6speed is a much stronger transmission than the T 10 and obviously has 2 more gears. Just my thought on a manual conversion.