4L70E Shift Kit 1982-2014, new and ready to install. Fits the 4L70E. Ships fast from the USA.
This kit is a Corvette-style servo upgrade, the classic first modification for the GM four-speed family. It fits 1982-2014 700R4, 4L60E, 4L65E and 4L70E transmissions and replaces the factory 2nd apply servo piston and housing with a larger-area aluminum assembly, sealing rings and springs. If your Silverado, Tahoe, Trailblazer SS, Camaro or tow rig has a lazy 1-2 shift, slips 2nd under load, or you just rebuilt the unit and want the 2-4 band to live, this is the inexpensive part that does the most for that complaint.
In this family the 2-4 band holds the reverse input drum for 2nd and 4th gear, and the servo is the hydraulic piston that clamps it. Line pressure acting on the 2nd apply piston squeezes the band through the apply pin, so the bigger that piston area, the harder the band holds at the same pressure. TransGo notes GM built 700R4 and 4L60E units with four different servo sizes depending on application, and the largest was the Corvette piston from tuned-port Corvettes and high-performance Camaros and Firebirds. Sonnax rates the Corvette servo at a .74 ratio, the biggest of the factory pieces. Fitting it to a truck that came with a smaller servo shortens and firms the 1-2 shift and adds 2nd gear torque capacity. Because servo release oil also cushions the 3-4 clutch apply, the 2-3 shift firms up as well.
A bigger servo adds holding power to a healthy band; it will not rescue one that is already burnt, and it will not cure low line pressure from a sticking EPC solenoid or worn pump. If 2nd and 4th are both slipping or the fluid smells burnt, read our 4L70E common problems guide and confirm line pressure first. Our 4L70E pump failure guide covers the low-pressure side, which can mimic a weak servo.
The listing covers 1982-2014 700R4, 4L60E, 4L65E and 4L70E units, the same span the factory Corvette servo fits. The servo bore is common across the family, but apply pin length varies by band and drum, so keep your existing pin unless the band or reverse input drum was replaced. This is an aftermarket aluminum assembly, not a GM part. If you are unsure your unit is part of this family, send us the year and VIN. Browse everything for these transmissions on the 4L70E parts page.
The servo sits behind a cover on the passenger side of the case and can be changed in the vehicle. Press the cover in, remove the retaining ring, and pull the old assembly; expect some fluid to drain. Lube the new seals with ATF, make sure the scarf-cut or D-ring seals are not twisted, and seat the cover fully before installing the ring. Many builders install it during a rebuild alongside a TransGo valve body shift kit, which TransGo designs to work with this servo, and a master rebuild kit if the band is worn. Top off with DEXRON-VI and check the level hot.
| Fits | 4L70E 1982-2014 |
| Part type | Shift Kit |
| Condition | New |
| Brand | GM |
| Ships | From the USA |
| Warranty | 1-year |
No. It is a Corvette-style 2nd apply servo kit: piston, housing, springs and seals. It firms shifts by adding band holding power, and pairs well with a valve body shift kit.
Yes. The servo cover is on the side of the case and comes out after removing the retaining ring. Expect a little fluid loss and top off afterward.
Yes. The listing covers 1982-2014 700R4, 4L60E, 4L65E and 4L70E transmissions, which share the servo bore.
Usually not. Reuse your existing pin unless the band or reverse input drum was replaced, in which case check pin length during the rebuild.
It firms the 1-2 and 2-3 shifts noticeably, but it is a factory-size upgrade, not a race calibration.
