Turbocharger Repair – Shaft Play

Turbocharger shaft play is a term that applies to the actual shaft which runs
between the intake and exhaust housings of a turbo. There are many types of
turbochargers that each will have acceptable shaft play. Most turbo units are
floating bearing turbos which means that the oil pressure is required to
stabilize the shaft completely. This means that there will be a slight
amount of shaft play in the unit when no oil pressure is present. Knowing the
tolerances of these turbos is key to diagnosis. Ball bearing turbos
will have no shaft play at all when they are in working order. Ball bearing
turbos are not as common due to the high cost of the units.

The tolerance for shaft play on a floating bearing turbo is enough
that it can be seen but the blades of the unit will not touch the sidewall of
the housing. If the blades of the impeller can touch the side with very little
force then the unit should be replaced. That said if the blades are forced to
touch the sidewall with excessive pressure then the turbocharger has just been
damaged by the person doing this. Shaft play in an in and out fashion is never
acceptable and means that internally there is serious damage to the
turbocharger.