Description
C6 CODE “R” SERVO SONNAX NUMBER K36528R
C6 
“R” Ratio Servo Piston Kit
Part No. K36528R
- Cover
- Assembly
- Pin O-Ring
- Pin PTFE Seal Ring
- Medium O-Ring
- Large O-rings (2)
- Cover Gasket
- Selective Return Springs (2)
Mid ’68-later
Since its introduction in 1969 with the 428 SCJ, the R code servo has remained the trick piece for C6 builders needing additional band apply force. Sonnax R code servo kit K36528R for C6 (mid 68-later) units features a no-leak pin which uses one O-ring and one PTFE ring to eliminate back pressure and leakage due to worn case bores. A replacement seal kit K36528R-SK also is available.
- More than 9 square inches of apply surface for more band apply force
- No-leak servo pin design allows the servo piston to be used in worn bores
- Two selective return springs allow for tuning of shift quality
NOTE: Some servo modifications involve blocking feed or exhaust passages in the case. These modifications must be removed. For proper operation of this servo, ensure that the exhaust passage and both oil feed passages are unrestricted.
This C6-R Servo performs as the Ford “R” servo. Due to the apply-to-release ratio, this servo delivers the best overall shift feel and timing. The C6-R Servo delivers positive 1-2 and 2-3 shifts. This Servo delivers a clean 3-2 kick down. Fits 1967 up only, will not fit 1966. Since its introduction in 1969 with the 428 SCJ, the R-code servo has remained the trick piece for C6 builders needing additional band apply force. Ford last offered an OEM replacement in 1992.
