• 4th Clutch burned
  • 4th Slip
  • Bushing failure
  • Bushing wear
  • No 4th
  • No Reverse
  • Reverse slip


OE bushing material composition allows premature bushing wear.


Restore critical clearances and resist untimely bushing wear by installing improved material Sonnax center support bushing.

AT-540 Series

Center Support Bushing
Part No. S29506468

OE Part No. 29506468

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OE center support bushings in Allison® AT-540 series transmissions tend to wear out prematurely due to sub-optimal material composition. This wear can lead to bushing failure, slipping/no Reverse, slipping/no 4th, and burnt 4th range clutches. Sonnax center support bushing S29506468 features superior wear characteristics, eliminating premature deterioration for trouble-free operation.

  • Direct fit, no machining necessary
  • Upgraded material composition for increased wear resistance
  • Material: Bimetal
  • Bushing Style: Precision
  • Housing Bore: 1.598"
  • Shaft Dia.: 1.466"
  • Width: 1.850"
  • AT-540 Series Center Support Bushing S29506468