Ring Gear Runout

1987 models equipped with anti-lock brakes incorporate a multi-tooth exciter ring which is pressed on the differential case located behind the ring gear assembly. Do not remove exciter ring to measure ring gear runout. A space is provided between the exciter ring and ring gear to measure ring gear runout.

If ring gear runout during disassembly exceeded specifications, the condition may be caused by a warped gear, or distorted or damaged case or foreign matter trapped between differential case halves or under ring gears.

To determine cause of excessive runout, assemble differential case without ring gear, then check as described below.

Install case in differential carrier without ring gear attached. Install bearing caps and adjuster nuts and tighten cap bolts to specifications. Tighten adjuster nuts to center differential side bearing. Mount a dial indicator and check runout of case flange and ring gear pilot. If runout at either point is excessive, install a new differential case. If runout is within specification, the ring gear is out of specification. When performing this check on a locking differential case the four compression springs within the case should be temporarily removed. This will prevent a false runout reading due to distortion caused by the springs forcing the case apart.