- 1-2 Quality poor
- 2-4 Band burned
- 3-4 Concerns
- 4th Band servo piston breakage
- 4th Slip
- No 4th
The overdrive servo piston cracks, allowing apply oil to leak. In addition, the OE servo cover bolts are not hard enough, which causes the cover to come loose, allowing the piston to cock and break.
The Sonnax overdrive servo piston is made from stronger materials to prevent cracking, while the hardened bolts included in the kit prevent the cover from coming loose.
Overdrive Servo Piston Kit
- Piston 88mm
- Hardened Bolts 6mm
The overdrive servo piston in JR403E units is prone to cracking, allowing apply oil leakage that causes poor 3-4 shift quality and burned bands. The OE servo cover bolts stretch and break under normal use. As the cover becomes loose, it allows the piston to cock and break. The Sonnax overdrive servo piston 62170-01K is thicker and stronger and will not break like the OE pistons do.
- Piston is made from billet aluminum for greater strength and wear resistance.
- The 88mm (3.46") 4th piston can be used to upgrade from the smaller 75mm (2.953") 4th piston when used with a larger piston housing.
- High-strength bolts will not stretch, and keep cover firmly secured.
Replaces OE 88mm piston. Will also upgrade 75mm piston if used with new piston housing.