1984 THM200

What would cause a delayed 1-2 with no upshift to 2-3? It is intermediate,just started today.

Has been real cold lately. Tranny was drained and filter change at 93k running Mobil 1 Synthetic.Only a small snowcone of debris at change.

Car has 103,000 and shifts fine otherwise,can be a tad lazy, with converter lock up.

That sounds like a modulator problem. But I can't remember if the THM200 even had one or if it is mechanical. Been a while.

I'm thinking a vacuum problem too,but not sure.Might be worth the part and check lines,waiting for additional confirmation.. Car hasn't been beat nor is it slipping ,still feel converter lock after final up shift and unlock when brake applied.

Weird

But I don't want to yank for nothing,at least I know someone who can rebuild.Perhaps I can get a shift kit and clutches.Would be nice to step up to a OD tranny but not sure if the car is worth the trouble.

That trans uses a throttle valve cable instead of modulator. Sounds to me like the valve that this cable operates is stuck, which was really a common problem. Usually sticks from something making metal, like a thrust washer failing. The transgo shift kit puts a weak spring behind the valve to aid in keeping this from happening. With engine running and in park, try jabbing the throttle several times. This may pop it loose.

That trans uses a throttle valve cable instead of modulator. Sounds to me like the valve that this cable operates is stuck, which was really a common problem. Usually sticks from something making metal, like a thrust washer failing. The transgo shift kit puts a weak spring behind the valve to aid in keeping this from happening. With engine running and in park, try jabbing the throttle several times. This may pop it loose.


Will try that thanks a lot,gives me the starting point of diagnostics. :cool: