Hi,

1986 700r4 with stuck TV valve:

I installed TransGo 700 Jr. shif kit
1-2 and 3-4 Sonnax pinless pistons
Gold shim in servo + extra spring provided for TGo kit (wiggle tested o.k. Estimate from 1 to 1.3/8 band wiggle from side to side)
Replaced broke servo's orange return spring 28 milimeters high for a new 30 milimeters high

Tested car running and all was perfect: 1-2 upshifts @ 17 MPH and 2-3 upshifts @ 24 MPH,

But, 3-4 upshift changed from 42 MPH to 55 MPH.

What could be the cause?


Thanks in advance,

Denis V.

 

Question:

Answer:

 

The Transmission most likely was suffering from Low TV (Throttle-Valve) Pressures...
Depending on the Position, and which Components in the TV Valve-Train were "Stuck" there are too many variables to say exactly the answer that you are looking for.

If I took Line-Pressure and TV Pressure Measurements prior to the installation of the TransGo Parts.
As well as disassembled the TV Valve-Train, and viewed their Positions and Conditions.
As well as Assembled the New TransGo Components.
As well as took Line-Pressure and TV Pressure Measurements again.

I could have given you definitive Answers.

However, most likely the TransGo Components have restored some if not all the TV Valve-Train Function...
The End Result is just a change brought from having that Circuit being in good health again, as well as some Line-Pressure and Boost Pressure Improvements.
The Line-Bias Valve-Spring change also plays a part in when the Pressure Increases occur in relation to the Throttle Percentage.


Nothing to be worried about.
Looks like things are NOW behaving as they should have been all this time.