Cummins/Onan GTA8.3 / GTAB.3 — Turbocharger Replacement
Repair & overhaul · Air system
For the Cummins/Onan GTA8.3 / GTAB.3, from the Cummins/Onan owner's manual.
Applies to: Cummins/Onan GTA8.3 engine
Before you start
- New turbochargers must be prelubricated before start-up.
- Use only anti-seize compound compatible with oxygen sensors.
Procedure
- Disconnect exhaust and charge air core piping.
- Drain coolant and disconnect turbocharger coolant lines.
- Remove capscrews from oil drain tube and remove oil supply line.
- Remove intake manifold pressure supply line from boost capsule.
- Remove turbocharger and gasket; clean sealing surface.
- Install new gasket and apply anti-seize compound to mounting studs.
- Install turbocharger and new gasket, torque 32 Nm [24 ft-lb].
- Install drain tube and gasket, torque 24 Nm [18 ft-lb].
- Install turbocharger coolant lines, keeping return line horizontal.
- Prelubricate new turbocharger with 50 to 60 cc clean oil.
- Install oil supply line, torque 15 Nm [11 ft-lb].
- Install intake manifold pressure supply line and charge air core piping.
- Operate engine and check for leaks.
Tools required
- wrenches Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Turbocharger mounting torque 32 Nm [24 ft-lb]
- Drain tube torque 24 Nm [18 ft-lb]
- Oil supply line torque 15 Nm [11 ft-lb]
Source: Cummins/Onan owner's 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.