Turbo 350 trans won't upshift from first gear.

What would cause a turbo 350 to not shift out of 1st gear?

It has plenty of fluid.
It has vacuum to the hose to the vacuum modulator.
That vacuum hose is brand new so not cracked or anything.
It does reverse and 1st fine.
When you drive it, it goes through 1st, then it doesn't shift. If you let off the gas at that point, it the rpm's will drop but the car is just coasting. You can give it gas and it will rev back to where it starts pulling in 1st again, but never upshifts. I tried manually starting in 1st then shifting to second, but nothing.

History - trans was supposedly rebuild some time ago and had sat for a year before I got it, then sat for a year before I was able to attempt to use it.

Any ideas?

I read somewhere that it could be a governor gear stripped or the valve behind it not moving for some reason. I have yet to attempt to check that.

Thanks
Todd

 

Could be the gov or the pass gear valve is stuck. If you take it out and flogg the thing as hard as it will go and it finally shifts up the gov has took over and the pass gear detent valve is stuck. If you flogg the shit out of it and it never shifts up the gov is stuck. Good luck !! >>>>.

 

Those are the same symptoms of the vacuum line not being hooked up. I would suspect a bad vacuum modulator, or it is severely out of adjustment. If you have a very skinny screwdriver, that will fit inside the vacuum port on the modulator, (where the hose connects) there is a screw inside there that you can turn to adjust the shift point.

 

if I was to guess...I'd say the gear was worn out on the governor. Pop the clip, pull the cover and it will slide right out to see. It's worth a look.

 

i had that happen to a TH350 , it was a stripped governor gear

 

Its a modulator problem.....

 

Stuck governor, or stripped governor driven gear. Put a little pan under it, and pop off the governor cover. It should pull right out. Teeth should be uniform, and the weights and plunger should move freely.

 

I vote for the governor as well. And they do come out very easily. Most tranny shops have them rebuilt on the shelf and you should be able to trade yours in .

Bob

 

Thanks for all the replies over the night. I went out there this morning before I left to take my son to school and go to work and I jacked it up in the rear and rolled under it and removed the cover to the governer and the assembly slid out easily. It moved in and out very easily and smoothly. I removed it and inspected it and it was not corroded or anything and was clean.

The plastic gear on the end was perfect. No chipped teeth. No missing teeth. No bent up or odd shaped teeth at all. Looked good.

The weights on the outside end moved freely and appeared to move as they should.

I cleaned up the cover and straightened out the edges where I bent it up trying to taop it out then replaced it.


I then looked at the vacuum modulator. It appears new on the outside. Now, when I was getting everything ready at first it had about 3 - 4 inches of vacuum hose on it and inside that hose was remnants of somethin a dirt dobber probably did, however I didn't see any hint of that in the little extension of the modulator itself.

I attempted to turn the screw this morning and I was unable to turn it. I had a lame screw driver though and I was grinding on it to make it fit better but running out of time, I may not have ever achieved the correct wedge at the end to match the screw.

I am assuming tha tteh screw should turn fairly easily, and also that the dirt dobber could have placed some trash up in there where the vacuum signal goes in to the modulator.

I am thinking that I will replace that if Ic an find one easily ehre in town.



Any other ideas based on that info so far?


Thanks again!

 

When you had the governor out and moved the weights did you make sure the little valve in the center was moving??

Just because the weights move doesn't meant that the valve is moving....

 

Modulator valve. Cheep fix. Car wont shift and coast when you let off gas. Yep

 

Doh! Didn't know to look for a valve moving with the weights. Dang!

 

cool. I will try this one next and if that doesn't do it, I guess I will pull that governor out again and check that valve thing with the weights.


thanks guys!!!!

 

OK, I figured it out.

I bought the modulator during the day when I was out of the office running around. I installed the modulator, but then when I had the car up in the air I decided to go ahead and pull the governor out again and check that the calve inside it was sliding in and out with the weights and it was not! So I used a small screw driver to give it a nudge and it finally started moving. With a little ATF it began to move freely and easily.

I took it for a quick drive around the block and it was shifting!!!!!! YAY!!!!

Thanks everyone for the help with this!!!!!!!

Todd