TH400 FMRVB to Manual/Auto valve boy

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FastRegalWE2

Wish I had another Buick!
Joined
Jan 10, 2004
Messages
1,886
I have a TCI Full manual valvebosy trans Im getting ready to put in. No modulator, no governor. I got my hands on a Hughes Performance Manual/Auto valvebody I could put in place. Questions is, besides adding a modulator valve and governor, what else would be needed to swap the valvebodies out and make it have the auto function?
 
You would have to re-install the front band and servo assembly.
You would have to re-install the center lip seal in the direct drum (and sealing ring on the center support) or block the passages ( you would have to look at the Hughes seperator plate) so it doesn't backfeed the low circuit in 3rd gear.

You would have to also re-install the 1-2 accumulator seals, and somehow get the checkball out of the accumulator drain passage. :mad:

There is a spring and checkball in the case that should fall out when you remove the VB, leave it out.

Real PITA because of the checkball driven into the case. They should supply a cup plug instead.
 
You would have to re-install the front band and servo assembly.
You would have to re-install the center lip seal in the direct drum (and sealing ring on the center support) or block the passages ( you would have to look at the Hughes seperator plate) so it doesn't backfeed the low circuit in 3rd gear.

You would have to also re-install the 1-2 accumulator seals, and somehow get the checkball out of the accumulator drain passage. :mad:

There is a spring and checkball in the case that should fall out when you remove the VB, leave it out.

Real PITA because of the checkball driven into the case. They should supply a cup plug instead.

dang, maybe I will just leave it be. We just got done rebuilding TH400's in school, Im not taking this one aprt that deep. Thanks for the reply. :biggrin:
 
Ck performance was working on a full auto valvebody with transbrake. But i dont think it is available yet.
 
Ck performance was working on a full auto valvebody with transbrake. But i dont think it is available yet.

I saw that awhile back. That was the first time I had even heard of that styl body. I think I will just run this one the way it is for now until I get the rest of the parts for the 4L80E conversion. I hae the trans but need all the rest of the junk to go with it. Gonna run that one manual so I can cut the cost of the conversion by $1K. Im trying to find a way to run that manual but retain the TCC lock up feature.
 
Using a full manual 4L80 isn't $1000 cheaper than using the electronic controller.
You can buy the TCI controller for $650 from Jeg's, Summit, whatever, and if you shop around you can get it for less than $600.
You might have to also use their TPS setup for another $200 if you don't have EFI or can't fab a TPS setup for your carb.

So $850 total max for the electronic control. The manual VB setup is ~$250 alone. Only $600 difference. Possibly only $400 if you have existing EFI.

You can use the TCC with the manual setup but you have to use a ballast resistor in the circuit to limit voltage so it doesn't burn up the TCC solenoid.
 
Using a full manual 4L80 isn't $1000 cheaper than using the electronic controller.
You can buy the TCI controller for $650 from Jeg's, Summit, whatever, and if you shop around you can get it for less than $600.
You might have to also use their TPS setup for another $200 if you don't have EFI or can't fab a TPS setup for your carb.

So $850 total max for the electronic control. The manual VB setup is ~$250 alone. Only $600 difference. Possibly only $400 if you have existing EFI.

You can use the TCC with the manual setup but you have to use a ballast resistor in the circuit to limit voltage so it doesn't burn up the TCC solenoid.


TCI was showing them at 1000 thats where I got that from. This is going on my (eventually) 87 GN so TPS is already present. Was also looking at the mechanical speedo conversion and trying to find a JW style bellhousing for it.
Know if the turbo 400 bellhosuing will bolt up? I have the Ultrabell on my TH400 already.
 
The TH400 UltraBell won't work.
You'll have to use an adapter plate to make it work.

Having an existing TPS saves you some trouble, they make a "Y" harness to plug and play the TCI controller. You can get the controllers for less than $600.
Even if the controller is $1000, the manual VB is $250+, so the difference is still only $750 in your case.

The actual difference is about $300 in your case and IMO I would go electronic without a doubt. Much better setup, controlled shift points and pressure, etc.

There is a Cable-X controller that converts the electronic speedo signal to mechanical. TCI also has one (maybe the same?).

You could also install a tailhousing that is setup for mechanical gears BUT you must have the proper output shaft (not fully splined) to use it so you can install the drive gear.
 
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