42932 - FORWARD DRUM UPGRADE (4R70W/AODE)

# 42932

FORWARD DRUM UPGRADE (4R70W/AODE)

This item is ordered on demand and is subject to supplier availability.

Please Contact Us to confirm Pricing and ETA

Compatible with ISS-equipped and non ISS-equipped applications.

Symptoms:

No Forward
Slipping gears
Broken clutch drum
Ratio codes

Cause:
OE forward clutch drum splits at snap ring groove due to manufacturing process, creating no or slipping forward clutch apply.

Correction:
Restore proper gear engagement and hold by installing sturdier, forged Sonnax forward clutch drum.

A common failure of listed Ford transmissions is cracking of the forward drum at the snap ring groove. The manufacturing process of the OE snap ring groove creates high-stress points around the circumference of the drum. The drum is active in 1st, 2nd and 3rd gear ranges and suffers the most abuse on a forced 4-3 kick down when it reapplies at higher pressure.
The concurrent pressure from the forward clutch piston combined with the high stress at the snap ring groove causes the upper portion of the drum to split and separate at the groove. Depending on severity of crack, this can result in no forward engagement or slipping in 1st, 2nd and 3rd gear. The forged, one-piece construction of the Sonnax Smart-Tech forward clutch drum eliminates weakness at these stress points.