Has anyone compared the different valve bodies between the performance coded trans and the passenger transmissions? What are the differences between the two such as the size of the passages of the oil flow, check ball size, etc… Can a passenger valve body be made into the performance version by modifying these items?

 

You could make these modifications for a quicker shift but not sure what else makes it the performance trans.

 

I don't have my 2005 chassis service manual in front of me right now, but there's a good chance the transmission section (pick your favorite year) contains all the differences, since it gives complete rebuild information. At least that's how the 1970 chassis service manual is.


I wouldn't surprise me if there are differences beyond the valve body, such as in the clutch pack.

 

I haven't seen all the possible combos but judging by what I have seen there are several differences. The tv valve is larger and the spring might be different on the "hp" vb. This can be swapped in along with a new spring. The line bias valve and accumulator springs are different and the shift springs have tensions that match the installed governor. This is why it isn't a good idea to mix and match vb and governors. It usually has poor results.
The governor on the "hp" trans have small weights and light springs to produce higher rpm shifts.
What vb/gov combo are you working with?
The "newer" units (relative term with a trans that gm last produced in 1990) received updates of some of the failure prone components. Pump rings, stator support shaft, sun shell, one of the plastic washers in a planetary was upgraded to a bearing.

The turbo regal and turbo trans am vb also got an additional switch in the vb to indicate third gear.

 

I think the valve body CASTING are basically the same, its the valve diameters, the sleeves they ride in and spring tension is what effects calibration. And on some hydralic circuits, a change in one valve or spring will cause a change in another area.

The BRF valve body is the Holy Grail of 2004r transmissions. It was used in the Grand National and T type cars. I think the code for the Turbo Trans Am is BRQ. Chris at CK Performance would be the guy to talk to, he knows those transmissions well.

 

At this time, I don't have anything to work with. Just inquiring about changing one to the other. I have an 85 service manual and there are differences noted between the OZ transmission and others.

 

http://web.archive.org/web/20070128173316/http://members.aol.com/powerrslid/thm2004r.html

Turbo Trans Am = TA
84-85 turbo regal = BQ

These turbo vb have a switch on 3 and 4 also.

Since you don't have anything, I would suggest picking up an AA code from a cadillac . That is what I am using currently and I like how it works.

OZ is the hp olds vb. what does the manual tell you is different about it?

 

I will have to re-read but I remember the servo piston is assembled differently. There are other diff to.

 

Yes, servo should be a "692" which is the same as what came in the bq trans. I use a sonnax as it retains the spring to avoid a downshift "clunk" that some of the other aftermarket pieces have due to eliminating the spring. The brf would have a "694" and is the largest of the factory 2004r. There is a larger unit that came in a 200. The ck performance is very similar to it.