







⚙️ Lock in power, shift like a pro – don’t get left behind!
The Sonnax 4th Gear Super Hold Dual Servo Kit (77767K) delivers 40% more apply surface area to dramatically improve holding power and shift quality in GM 4L60, 4L60E, 4L65E, and 4L70E transmissions from 1982 onward. Designed to fix common 3-4 shift issues and band failures, this easy-to-install kit is a must-have upgrade for performance enthusiasts seeking reliable, smooth gear transitions backed by a 1-year warranty.
| Manufacturer | LANHO AUTO PARTS |
| Brand | 1409KMT |
| Model | KMT-OT001426 |
| Item Weight | 1.23 pounds |
| Package Dimensions | 3.82 x 3.62 x 2.52 inches |
| Item model number | KMT-OT001426 |
| Exterior | Machined |
| Manufacturer Part Number | KMT-OT001426 |
B**0
Great upgrade
Great and easy upgrade for the 4l60E. Easy to install and you will notice the difference immediately
A**R
This is a KNOCK OFF.
I verified with the original manufacturer. Do not trust the information on this listing.
R**.
Doesn’t fit
The seals were the wrong size causing the servo not to travel correctly. In my case it’s a 10 hour job to remove them and I neither have the time or inclination to do that removal in triple digit heat.
L**D
NOT a SONNAX part,JUNK!!
This is a Chinese copy. It will probably work, but don't know yet. Just so you know what you're gettingUpdate; This part never did work, caused several hours of diagnosis and possible damage to the transmission band. The picture shows what it looked like after 10 miles in my transmission