A/T - Extension Seal Leaks
File In Section: 7 - TransmissionBulletin No. 46-71-08
Date: December, 1994
Subject:
Transmission Extension Seal Leaks (Install Revised Seal)
Models:
1988-94 Chevrolet and GMC Truck C1-2, G, S, M Models with 4L60 (MD8) or 4L60-E (M3O) and One-Piece Propeller Shaft
CONDITION
Some vehicles may experience a leak from the transmission extension seal.
CAUSE
This leak may occur if the seal lips are damaged by a corroded slip yoke barrel. As the rear suspension moves, the slip yoke slides past the seal lips. If the slip yoke barrel is corroded, seal damage can occur resulting in a leak.
CORRECTION
Install a revised seal P/N 24201470. The seal features a flexible boot which covers the slip yoke barrel to prevent corrosion. This seal is used in production starting with the 1995 model year.
SERVICE PROCEDURE
Refer to the appropriate year and model Light Truck Service Manual, Section 7A - Automatic Transmission On Vehicle Service for correct seal replacement procedure.
Tailshaft Seal:
Important:
This seal has a small vent hole in the flexible boot. This hole must be installed facing down or the boot could collect and hold water. Use sandpaper or crocus cloth to clean any rust or corrosion off the slip yoke barrel before installation. If the slip yoke barrel is not clean, the seal could be damaged.
Parts Information
P/N DESCRIPTION QTY
24201470 Seal, trans extension oil 1
Parts are currently available from GMSPO.
Warranty Information
For vehicles repaired under warranty, use: Labor
OPERATION DESCRIPTION LABOR TIME
K6360 Seal, Extension Use Published
Housing Rear - Labor Operation
Replace Time