Article 1105 - Distributor Upper Bushing Failure

TSB #70 - June 23, 1967
(All Car and Truck V-8's Except 289 CID)


Some FE and FT series engines have been built in which the thrust boss for the distributor drive gear was machined too deeply in the block. This machining discrepancy will result in premature distributor upper bushing failure and/ or seizure because there is not a proper surface for the distributor gear to thrust against.

If a distributor upper bushing failure should occur, it is imperative that the cylinder block machining be checked using the following procedure:
    1. Remove the failed distributor.
    2. Inspect the camshaft gear and cylinder block gear thrust surface for any damage.
    3. Install a new distributor in the cylinder block opening. NOTE: Do not install clamp.
    4. Hold distributor in position and rotate engine several revolutions.
    5. Apply firm downward pressure to the rotor end of the shaft then attempt to move the distributor body in a "Up" and "Down" direction. If the cylinder block is machined properly, there should be .008" to .020" free movement at the housing. If the movement is as specified, the engine should be continued in service. If it is not possible to move the distributor body as specified, it will be necessary to replace the cylinder block using normal service procedures.

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