tranny no shift from 2-3

[deepseeman]

ok gents,
I have read several forums, but still cant find the answer. so here are my symptoms and the things i have done.

Symptoms- running great til last night. tranny wouldnt shift into 3rd. checked fluid, quart low. topped it off. still no change. tried manually shifting. no go. checked vacuum this morning and its good. lines are fresh. fluid doesnt smell burnt.

recent maintenance- replaced tranny 6-8 months ago, also replaced t/c, all vacuum lines and modulator and vacuum valve.

do you gues have any suggestions?

 

[deepseeman]

just replaced the modulator again and still no love. she wont go over 30 mph

 

[doghead]

Try connecting directly to the modualator valve without the VVR connected.

 

[deepseeman]

ok, just did that now and she is still stuck.....

 

[doghead]

One more "test".

Try with no vacuum line attached to the modulator.

 

[doghead]

Where and how much vacuum did you have when you checked that?

Basically, with full vacuum supplied to the modulator valve, the trans should shift based on the mechanical governor. Since it did not, I suspect your governor is the issue.


I believe it should also shift off the mechanical governor with no vacuum as well.

I'm only about 50% confident that I am correct on this one.

 

[doghead]

One more thought, test your vacuum down at the bottom, at the modulator valve connection without the VVR connected. Compare this to what you got at the vacuum pump. This will test your lines all the way down to the valve.

 

[deepseeman]

15'' of vacuum. just conducted test drive with no vacuum line attached and it still stuck. no faster than 30.

 

[doghead]

I'm out of thoughts, sorry.

I would pull the governor and look for anything broken.

 

[deepseeman]

****....thanks for the help. Im off to the tranny shop....

 

[Barrman]

I guess you already left, but if not. Pull the 4 bolts that hold the governor cover, pull it off and remove the governor. Move the arms and make sure the plunger inside them is moving free. Put it all back together and see if it is better.

 

[dstang97]

Disconnect the only wire to the transmission. This is your kick down.

 

[doghead]

There is a reverse light wire as well!

 

[dstang97]

There is a reverse light wire as well!

On all the th400 I have had there is only one wire and that's for the electronic kick down from 3rd to 2nd. Reverse is done on the steering column. Iirc it's a switch with a blue and green wire. Are you thinking of a sm465?

 

[dstang97]

When I first got my cucv I could not get it running. 6moths later she fired up. Driving down the road it toped out around 30mph. When I was messing with the truck I realized the kick down was cut so I extended the wire and put on a new connector. Then determined the guy I bought it from lied to me. I put in another $100 dollar th400 and off I went. Then 2 years later talking with Asgar he told me the switch will fail and you will only have 1st and 2nd but if you disconnect it will work. Good think I kept the original tranny. That wire is fed from a switch off the "gas pedal"

 

[doghead]

I'm sorry, Your right! I was thinking of the 4wd light wire.

That's what I get for drinking brandy for a cold first thing in the morning, before my coffee.

 

[dstang97]

I'm sorry, Your right! I was thinking of the 4wd light wire.

That's what I get for drinking brandy for a cold first thing in the morning, before my coffee.

Yeah, not like you. Lol