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

No issues and nice upgrade from stock plastic piston with the rod. I noticed slightly better shifting

2003 Suburban with 4L60E transmission. My 1-2 shift was harsh only when cold. Dropped the pan with no interference on exhaust crossover pipe and bent the shift bracket over a bit to remove. I just re-used the original springs. Installing was a breeze. Check out YouTube for a video with all the instructions. This improved my 1-2 shift by 75%. Might have had even more improvement if I had replaced the larger spring - who knows? Remove close to a gallon of ATF from the pan and replaced about the same. Chevy calls for Dexron III but the Dexron VI is backwardly compatible. (Don't forget to order more like I did). For the price and 2 hours worth of elbow grease it was worth it!

So far this kit has made the 1-2 shift good and firm.After pushing the OEM pin out of the center of the housing, I taped the large ball into the hole. The ball was pretty loose in the hole and didn't take much to pop it out. I didn't want to take any chances so I took a large metal chisel and put it across the hole and gave it a few taps. This deformed the hole opening enough that the ball could not come out.After several days of driving, so far it's working fine.

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.

Easy install. Dont go crazy with the ball braring install. It only needs one or the other not bothStake it gently. All in all a good set up.

Replaced the stock 1-2 and 3-4 accumulators with these. The difference in overall build quality of the part vastly improved my shifts. It uses two seals to keep the piston square in the bore, eliminating the guide pin, which seals any possible places for fluid to leak. A very minor modification is necessary when using in the 1-2 position, which requires tapping and staking a check ball into the housing. Easy as can be.

I was having issues with slip or delayed shifting from 1-2 on a Trailblazer. After some research and consulting with my transmission rebuilder he suggested trying a pinless accumulator. First, make sure to scotch pad the bore and oil the o-rings. I re-used the stock large outter spring and installed the Sonnax piston over the spring. You can also bump line pressure via the EPC torx. Fair warning: 1/4 turn is all i needed (i did this prior to installing the piston as step 1. did not eliminate delay but helped), you can go too far and cause damage. (DISCLAIMER: I am not a transmission builder so proceed at your own (transmissions) risk.) There is no longer a slip into second and the shifts are predictable based on throttle input. The more input, the firmer the shift.

2007 Silverado shifted so hard I thought I was loosing my driveshaft. Replaced and now it is crisp and I'm happy.