Decorative zipper
Line Pressure Booster Kit

Sonnax Zip Kits®

The First Step in Correcting Common Shift Problems

It's easy to restore and extend vehicle shift quality with Zip Kits. Uniquely designed Sonnax parts target the root cause of valve body complaints and stop critical circuit pressure losses in the most common problem areas of the transmission.

Watch the video below to learn more about Sonnax Zip Kits!

Zip Kit box and instruction sheets

No Special Tools Required

  • Simple parts require NO special tools or reaming for installation
  • Will not permanently modify the valve body core

Tackles the Big Picture of Shift Problems

  • Resolves critical hydraulic pressure loss caused by commonly worn components
  • Extends the life of high-mileage units

Detailed Tech Booklet

  • In-depth tech guide explains diagnostics and installation steps
  • Identifies more Sonnax fixes for other worn areas in the valve body causing transmission problems

See what people are saying about Zip Kits:

  • I installed our first Zip Kit on a U140F, nice kit and additional information. What was really nice: to have at your fingertips the vacuum testing locations and the effects of the wear in that bore. Without this information I might not have vacuum tested and missed this problem. Nice kit, Sonnax."

    K. Mumie
    Foran's Transmissions
    Minersville, PA

  • We had a 2008 Range Rover diesel 157,500km with drivability issues. We stripped the v/b and fitted all components from Zip Kit, reinstalled v/b, new ATF and new filter, then road tested the vehicle home. Well done, boys, this Range Rover drives 100%. I didn't even reset the adaptation, it drives real good."

    S. O'Connor
    A & M Gearbox Centre
    Dublin, Ireland

Zip Kits