Differential - Additive Recommendations for G80 Axles
90chevy03Number: 90-139-4A
Section: 4A
Date: January 1990
Corporate Bulletin No.: 964201
Subject: LOCKING DIFFERENTIAL LUBRICANT
Model and Year: 1981-90 ALL LIGHT DUTY TRUCKS EQUIPPED WITH G80 REAR AXLE
TO: ALL CHEVROLET DEALERS
Chevrolet Motor Division does not recommend the use of any limited slip additives in light trucks with G80 axles. Rear axle additives delay the engagement of the locking mechanism and may decrease axle life.
The recommended lubricant for all light truck rear axles, including G80, is SAE 80W-90 GL5 (GM part # 1052271). Trucks exhibiting rear axle chatter should be drained and refilled using the rear axle fluid indicated.