I have a '90 Dakota was a 5 speed now is an auto. swapped out new process 535 7 or 8 years ago and put in a 904 auto from a '80 lebaron. Just last week my tranny wanted to shift into 2nd from D when it started warming up. Everything as far as I can tell is good. Oil is still red not burned I have tried adjusting the kickdown linkage the shift linkage is good. If anybody has any answers it would be awesome if you could help. THANKS VERY MUCH Marsall

 

That sounds like something is stuck or clugging part of the valve body.

Have you also adjusted the kickdown cable/linkage at all?

 

I have adjusted kickdown yes. Since it used to be a 5 speed I bought an after market B&M ratchet shifter which hasa cable. I can put it in drive when it is cold, it goes through the gears until it starts to reach operating temp. If I lock the shifter in to 2nd from a stop it will shift 1st to 2nd. A friend of mine said it could be the valve body seperator gasket might have {split, broke, blown} causing it to loose pressure does that sound like that might be it. I am DUMB when it comes to automatics. Another thing he suggested is the governer I have no idea where it is or what it does. I am truly stumped. I do appriciate the feed back thank you very much Marshall

 

At this point here I would look for a transmission book to help. If it's working when cold but not when hot, then there is something up. I'd look at the gasket first as the governer (on the valvebody) would start acting up right from the beginning.

 

Does a 904 and 727 share the same valve body?

 

yes the valve bodies are "almost" exactly the same. they will physically bolt on if U swapped em'. But......dont do it unless you have no other choice. valving may be different from one to another.

 

I would guess governor.
Is this a "lock-up transmission" ( I am not sure because of the year). If it is, then the valve body would be specific to the lock up trans

 

For what it is worth, The aftermarket valve bodies such as Cheetah reverse manual valve bodies are the same with both transmissions. I believe the valve bodies are exactly the same depending on the years. I know that some years have a partial kick down feature so if you swap the valve body from an earlier transmission (earlier than around 73), then you will lose the partial kick down feature. That would have nothing to do with swapping from 727 to 904

 

I serviced the trans and cleaned out the valve body. It does shift into drive now but at about 45 50 mph. When I am slowing down it shifts into 2nd around 35 40 mph. could it still be the governer? The trans I am guessing is late 70s early 80s. It came out of a 1980 LeBaron that replaced its original trans it came from a wrecking yard. One more thing where exactly is the governer? Is it on the valve body itself?