In the moment, I am rebuilding my TH700R4. I changed the seals, the clutches and i installed a TransGo Reprogramming Kit Stage 2/3 automatic version.
I followed the instruction guide. Today, i installes the 2-4-servo and made the band adjustment. The band clearence is Ok. But iīve seen, i use a 2nd piston with the number 554. TransGo say "Donīt use the 554". Why canīt i use my 554-piston ? I donīt understand. The clearence is Ok !!!
Please help me !

 

Im assuming youre talking about the servo piston. Im also guessing youre using the stock 2nd piston which doesnt hold much pressure so youre suppossed to at least replace it with a corvette style one.

 

Today, I heared, the 554 piston is for V6 engines. Iīll go with a 553 piston !
I ordered a .471 boost valve. I hope, it will be ok. Do I also need a reverse boost piston ???

 

oops/--Int rev valve.
if you like to manually shift first to second it firms things up. not required all that much, more like a gizmo and sounds cool.
While the valve body is off don't forget to install the better TV valve with return springs.
I prefer to install a partial JR transgo kit also to get the 1-2 accumulator springs, and don't block the passage in the 4th accumulator I just flip so that the spring goes in first and piston second. I definately drill all holes in the separator plate to the max size. .156" and .110"............hope that helps some.

 

I changed the 554 to the 553 piston and changed the .422 boost valve to a .472. Yesterday, i moved the tranny to the car. I canīt drive on the road because i havenīt a license plate till may. I "drived" on the jack stands. I selected R,(D),D,2,1, the wheels turn. I selected (D) and the 1-2 shift looks good, but it doesnīt shift 2-3 and 3-4. I think, I must drive on the road to check everything allright.

I did all the holes and plugs like in the instruction guide. I didnīt forget the better springs in the TV-valve.. :-)