mnm8977

I am getting ready to do a trans service on my 08 Silverado CC 5.3/4L60e. I am thinking about doing a few upgrades while I got the pan off. The truck has 60k on it and trans works perfectly fine and is 100% stock. Only other mods to the truck include a Magnaflow cat back and Volant CAI. Tune is stock for now, but I plan on purchasing HPT in a couple of months and getting into tuning. I plan on replacing the pan with a Mag-Hytec pan installing a Tru-Cool 40k cooler and doing a servo upgade. I'm still undecided on installing a shift kit or not. I have read mixed reviews in the forums. My main goal is to increase the life of the transmission and possibly firm up the shifts a little bit. I don't want hard, tire chirping shifts. Here are the questions I have.

1. Has anyone here used Sonnax's pinless accumulator pistons or their performance pack?

2. Is a shift kit going to hurt the life of the transmission? I know faster shifts seem better, but won't increases in pressure cause more stress on other components?

3. Corvette or Super Hold Servo from Sonnax?

Any advice or experiences with these products would be greatly appreciated.

06Sierra2

im running both the vette servo and the pinless acumulator pistons, have been for about 15k HARD miles. I go wot on it about daily. The shift kit is a great idea for firm, fast shifts, but if you are already buying HPT tuners you can increase the shift pressure electronically also via tuning. you dont want to do it both manually and electronically, or so i have heard. I skipped the shift kit and just ran the above mods and the tune and its doing great so far at about 74k. And like i said, i run it hard.

mnm8977

What benefits did you get replacing the accumulator pistons? Did you replace the fourth apply piston too?

06Sierra2

Honestly i cant remember, but i believe i did both of them. i had a shop do the install over a year ago. I remember reading that it was a good mod and is cheap to do so i went ahead and had a reputable shop do it for cheap. The pinless accumulator supposedly has less chance of breaking....everything has been holding good so far for a relatively "stock" 4l60e in a heavy crew cab, knock on wood lol

mnm8977

Thanks for the info. Think I'm gonna forgo the shift kit for now replace all three accumulator pistons and do some tuning. Worst case scenario, I will change it up when it comes time to tear down the transmission and do a build up.
Has anyone used the Sonnax billet servo and fourth apply pistons?