GM Full Size Vans 1967-1986 Repair Guide

Rear Axle Differential

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FLUID RECOMMENDATION



Rear axles use SAE 80W-90 GL-5 gear oil. Positraction® axles must use special lubricant available from dealers. If the special fluid is not used, noise, uneven operation, and damage will result. There is also a Positraction® additive used to cure noise and slippage. Positraction axles have an identifying tag, as well as a warning sticker near the jack or on the rear wheel well.

FLUID LEVEL CHECK



See Figures 1, 2 and 3



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Fig. Fig. 1: The rear axle filler plug may be in either of the two locations shown here



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Fig. Fig. 2: Remove the filler plug from the housing with a ratchet



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Fig. Fig. 3: If needed, add the fluid through the filler hole

Lubricant levels in the rear axle should be checked as specified in the Maintenance chart. To check the lubricant level: