I've read many threads on various sites and have only found speculation and rumor about the J-mod on the 4R75E/W transmissions. I'm looking for somebody that has actually done or attempted it on this transmission, or knows as a matter of fact that it can or can't be done. Either way, I'd really appreciate details.

And before somebody post that I should just get a tuner, I already have one. I'd prefer to improve the shifting mechanically rather than turning up the line pressure. With the tuner, the shifts can be a rough around the edges at times.

 

Valve body from www.troyerperformance.com

 

considering it's the same valvebody as the 99-02 valvebody in the 4r70w i don't see any reason you couldn't do it.

 

Yeah, but why pay $300 if I can do it myself?

Back to the original question. Looking for somebody with first-hand knowledge or experience J-modding the valve body in a 4R75E or 4R75W.

 

the different valve bodies are 97-00. 01-03 and 04-08. The last time I was into a 4r75 the holes on the separator are right at jerry's (Jerry is the guy would designed the 4r70 trans and posted the j mod) recommendations or real close. The springs I do not know about. You could look into the 1-2 accumulator spring as well as the 2-3 one but you will not need to modify the separator plate.