"Powr-Lok" Differential Service Bulletin

The downloads (100-200K JPEG's) on this page are from Willys Motors Service Bulletin No. 500 dated December 14, 1960, from the collection of Bruce Agan. It provides details on the operation and service of the Powr-Lok limited-slip differential, which could replace the standard differential in most Jeep axles, with the exception of the Model 53 axle found in some Jeep trucks. A CJ-3B prior to S.N. 57348-33148 will also require new axle shafts (see Page 8).

The Powr-Lok can be identified by a brass plate on one of the housing cover bolts, stamped with the letter "T" or the notation "Use limited slip differential lube only."

• Page 1 -- Principles of operation.
• Page 2 -- Diagram of operation.
• Page 3 -- Diagram of turning a corner.
• Page 4 -- Service information continued.

• Page 5 -- Reassembly diagram.
• Page 6 -- Testing the differential.
• Page 7 -- Chatter and backlash.
• Page 8 -- Vehicle model chart.

Thanks to Bruce Agan. -- Derek Redmond

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