We here it every day.............. "My Turbo has too much play"
Turbochargers are expensive so its understandable that vehicle owners are worried about play in the Turbos shaft. We have these queries raised not just on old used Turbos and reconditioned/ remanufactured and even BRAND NEW GENUINE UNITS!!
Turbocharger design means that the rotor assembly (shaft and impellers) float on a layer of oil during operation for efficiency, to keep temperatures down (spinning in some cases over 250,000rpm causes a LOT of frictional heat) and to ensure minimal wear. In order for this to happen, a clearance is required between bearing to shaft and in the case of a floating bearing set up between bearing to housing also. Different manufacturers have different clearances especially in differing specifications of their Turbochargers from a radial clearance of less than 0.2mm to over 1.1mm radial in others. When the engine is running and oil pressure is present, these clearances are filled with pressurised oil, removing the free play and ensuring there is no direct component contact whilst in operation.
When you "have a wiggle" the unit is cold meaning all the components are in their smallest state and there is no oil in the vital clearance areas, let alone pressurised oil. This can result in a scary amount of play to the novice.
OE manufacturers and professional turbocharger reconditioners spend large amounts of time checking dimensions dimensions and clearances at multiple stages along the build procedure and wont sign off a job unless the final product is in tolerance.... It would be suicidal as the unit would not only perform poorly, but would last a short time indeed.
Turbo Rebuild, being a professional Turbocharger reconditioner for many years have the knowledge and experience to ensure your new or reconditioned Turbocharger is to the correct specification and together with our calibration equipment can ensure it performs 100%. We are not a "fitter" type company that buys complete Chinese inferior cartridges with no production history etc and simply bolts them in the old housings. We in many cases build units from scratch from component form right through the balancing stage and finally the calibration stage and log all data for future reference.
This video shows a Brand New Garrett GT1749V Turbocharger from the Audi/VW 140BHP BKD engines. This unit is unused and is the Genuine item. Just take a look at the video of the play found. Garrett GT units tend to have quite tight clearances compared to other units and still, theres a lot of play!