A/T - 700R4 Lubrication Update

Transmission:
4L60/700-R4

Bulletin:
# 9001003

Subject:
Rear Lubrication
Correction

Date:
Jan 1990

Rear Lubrication

Excessive wear on the reaction planetary washers (rear planet) can be caused by loss of rear lube oil and inadequate distribution of the lube oil.

Stator Support

The rear stator support (Figure 1) bushing and the input housing seal help control (contain) lube and support the input drum. The rear stator support bushing is often worn as much as .003" and still may look perfect. This wear will allow lube oil to leak past the bushing into the area behind the reverse input drum.

BULLETIN
RECAP

THM 700-R4 Lubrication
Correction

^ Replace the rear stator support bushing

^ Replace the input housing seal

^ Grind 4 vee slots into the rear of the reaction sun gear.








Input Housing Seal

The input housing seal (Figure 2) can be stretched more then .020"oversize, once again allowing a loss of lube oil. ALWAYS replace the input housing seal and rear stator support bushing to direct as much lube oil as possible down the output shaft to the rear planet.

A very good, low cost modification to improve lube flow to the planetary washers is to grind four slots in the reaction sun gear (rear). Figure 3. These slots should be 1/16 to 1/8 deep and wide vee shaped. Grind 4 of these slots, evenly spaced, on the back of the rear sun gear. These slots, which are in alignment with the planetary washers, will sling lube oil directly into the pinion washers. Giving extra attention to these areas will greatly help the life of your 700.

FOR ADDITIONAL INFORMATION:

ATRA Bulletin
S I L 87-1
S I L 85-31