Sonnax 4L60 4L60E 4L65-E & 4L70-E Pinless Accumulator Piston Kit

What I like about this is that it a metal pinless double seal Piston Assembly. And it has helped my shifting alot between 1and2

Fixed my sloppy slide and bump 1-2 shift on my 2005 GMC Sierra Crew Cab with a 5.3l and a 4l60e. It started shifting weird out of the blue coming up on 250 000 miles or 400 000 kms. I changed the fluid, filter, shift solenoids and a new accumulator housing with this sonnax piston installed. Now it's a nice solid feeling quick 1-2 shift. Now I'm noticing a hesitation during the 2-3 shift under light to moderate acceleration so I'm thinking of replacing my stock servo with a corvette servo.

Bought this product after researching my hard shift into second gear. The shift is smooth again! But still get ocasional hard shift but not as bad. 02 suburban 1500. It is not hard to install after dropping the trans fluid pan.

Thank you im very satisfied im a mechanic and i recommend this item

It wasn’t a “snap” to install but I didn’t expect it to be. It was installable within a reasonable level of technical skill, even on the ground I was done in under two hours from start to finish. I would recommend the corvette servo mod in conjunction with this. My transmission had sloppy shifts from 1-2 and an rpm flare from 2-3. I was looking at a $1500 rebuild but the issue seems to be resolved with these two mods.