Cummins/Onan — VT-50/ST-50 Assembly
Repair & overhaul · Rotor assembly
From a Cummins/Onan service manual covering: ST-50, T-18A, VT-50. Check it applies to your exact model before use.
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Before you start
- Do not over torque the nut; this will deform the shaft
- Do not exceed recommended V-band clamp torque
Procedure
- Check turbocharger bearing end clearance on shaft; should be 0.006 to 0.010 inch [0.15 to 0.25 mm].
- Install insulation pad and heat shield on bearing housing.
- Position sealing rings in grooves on turbine end of rotor shaft and insert shaft in housing.
- Insert bearing over shaft into bore and position bearing insert over bearing flange.
- Install new O-ring and oil seal sleeve assembly into diffuser plate.
- Install diffuser plate; press compressor wheel on shaft; install new locknut torqued to 20 to 24 ft-lb [27 to 33 N-m].
- Install collector housing and torque capscrews to 5 to 7 ft-lb [7 to 9 N-m].
- Insert rotor assembly in turbine housing and install V-band clamps torqued to 32 to 36 in-lb [3.6 to 4.1 N-m].
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Rotor nut 20 to 24 ft-lb [27 to 33 N-m]
- Collector housing capscrews 5 to 7 ft-lb [7 to 9 N-m]
- V-band clamps 32 to 36 in-lb [3.6 to 4.1 N-m]
Source: Cummins/Onan service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.