hey
so got a little problem is made my front end suspension new then cruised about 100 mils to open the season. i parked and wanted to continue after 1hour as a checked that my th350 won´t shift out of 1st

- P R and N work fine.
- D stick to 1st
- Found a little vacuum leak in hose. thought that was the failure- replaced it - checked vac --- still in 1st
- fluid is to full and clear red -check
- kickdown is not connected

So i ordered today a New Modulator hopefully this will it be.

I read that the upship mecanism is only vacuum controlled.

If its not the modulator what could it be ?

Any check plans?

Alex

 

Check the governor to see if the weights are stuck. Soak the governor in parts cleaner or brake cleaner till the weights move freely.
Worked for me when my TH 400 wouldn't shift out of first.

 

thanks fot the info - is there comming out any fluid when opining the governor case ?

just in case when doin that in my parking lot :-)

 

There might be a little. Put a shallow pan under the area.

 

okay ill try that - i got a garage 5 miles away in the city - can drive the car slowly in the city to the garage damage the tranny ? or is that no problem ?

 

Does it shift out of first eventually like around 42-45 mph? If so you probably still have a vacuum leak to the modulator. I'm sure you have a myriad of vacuum lines on that car not to mention those crappy plastic "T's". I've had them crack before and they are hard to detect if not completely broken in two.

 

Nope it never Shirts out of 1st engine rpm increases until 6k no Shift....

I checked all Lines and measured vac Direct at the modulator - all okay

 

X2 on the governor.

 

Sorry x2? What exactly do u mean?

 

If the new modulator doesn't solve the problem then follow these next steps:
1. Be 100% sure you do not have any vacuum leaks. If you have the steel line running down to the trans be sure its not plugged up. Make sure the vacuum source is coming directly off the intake and NOT off the carburetor.
2. Check the kick down cable assembly for bind and proper adjustment.
3. Check the governor as mentioned. The teeth on the driven gear can wear out. So check it for function and damage.
4. Drop the pan and inspect its contents. Large amounts of clutch material means the frictions n steels are worn out. Time for a rebuild.
5. Before dropping the trans do one last check....pressure check(s). Thats the definitive way of trouble shooting a hydraulic pump(aka transmission). Low or no pressures mean the same thing as number 4.

X2 means: me too or I agree with the previous post etc...

 

I think it's the governor as well. At the very least it's pretty easy to pull and check, my experience with the modulators going is it will still shift if you are on it hard.

Note: I said an issue with the modulator because you stated that you checked the vacume at the modulator already.

 

Hey guys
Good news. First i found out that i have a TH400 sorry for that but Problems are the Same.

I Checked the governor as you can see in the attached file the gear Looks worn

I think that is it....

Alex

 

You're going to need a new or a good replacement for the governor. I'm pretty sure you can't get replacement gears.
Let the community know what type and year car you have. Maybe someone will have a new one or a spare used.
Oh and change the fluid and filter. The missing material in more than likely in the pan and converter.

 

Ouch
I have dozens of parts trannys
There are millions of them in the US, and pretty much every GM has the same part. They do vary the weight somewhat and whatnot, but ANY good one has got to be better than that.

 

I'm looking at a TH350 governor that I keep at my desk here at work. It looks as if the gear is held on the shaft with a roll pin. If the TH400 governor is the same, it would be fairly simple to drive the pin out and replace just the gear with a good one from a donor governor. This way you could retain the original (correct) weights/springs so as not to alter the shift points.

 

Hey
I ordernd this: http://bit.ly/1iRRn0G
Meanwhile i use the governor from a g20 van from a friend;-)

His governor gear Looks after 200k mls like new...
The question is how could my one getting so worn?

Alex

 

Issue with the output shaft maybe. Like a worn bushing, is the seal at the rear of the transmission leaking?

 

That is a good deal well played.
I may be ordering this item.

 

Inspect and check the mesh between the drive gear on the output shaft and driven gear. Use pattern grease used to setup a rear end ring n pinion. Likely just a bad plastic gear but it doesnt hurt to inspect.