TURBOCHARGER (T18-A) REPAIR (CONT).
14. Install new piston ring (17) in groove of new thrust
spacer (18) and place thrust spacer over shaft of wheel
and shaft assembly (8) and into bore of backplate (14)
and thrust collar (12). Do not force piston ring seal into
15. Install impeller (19), at room temperature, on shaft of
wheel and shaft assembly (8) and secure as follows:
Oil threads of locknut (20) and area of impeller
face that will be under the nut with lubricating oil.
Install locknut (20) and tighten to 125 to 150 in-lbs
(14.13 to 16.95 Nm) torque. This will seat
impeller (19) against thrust spacer (18).
Loosen locknut (20) and then tighten to 35 to 55 in-
lbs (3.96 to 6.22 Nm) torque greater than drag
Drag torque is the amount of torque required to move the
nut on threaded portion of shaft before contact with the
Tighten locknut (20) for shaft stretch of 0.009 to
0.010 inch (0.23 to 0.25 mm), using a T-handle or
If shaft stretch cannot be measured, turn locknut
(20) an additional 110 degrees after step (c).
This procedure is valid for T18-A turbochargers
having 7/16 inch (11.11 mm) or 3/8 inch (9.52