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Locking Differential - Revised Lubrication

File In Section: 4 - Drive Axle

Bulletin No.: 66-42-03A

Date: August, 1996

SERVICE MANUAL UPDATE

Subject:
Section 4B7 - Locking Differential, Revised Lubrication Information

Models:
1996 Chevrolet and GMC C/K Models

This bulletin is being revised to change the models applicable and to correct the lubrication Information. Please discard Corporate Bulletin Number 66-42-03 (Section 4 - Drive Axle).

The lubrication information on Page 4B7-11 in the 1996 C/K Service Manuals is correct.

^ Use SAE 80W-90 GL-4, GM P/N 1052271, oil when adding or replacing oil in the differentials supported in Section 4B7.

^ DO NOT use SAE 75 W-140 GL-5, GM P/N 12346140, in the differentials supported in Section 4B7.