1969 Dodge Dart issue with installing axles after thrust block removal.

All else being equal, Green bearings equalize the inner spline engagement side to side.

OEM adjustable wheel bearings cause the axle spline engagement to vary unless you blueprint the axle lengths. Measure the axle flange stand-out on both sides of any stock 8 3/4″ rearend. Because of production tolerances, the single adjuster causes the axle flange (and inner axle spline) to protrude farther on 1 side than the other.

I have a 5 gallon bucket full of stripped out (2 piece style clutch/power-lock) side gears due to insufficient spline engagement on one side caused by the single OEM threaded adjuster.

The primary culprit is the poorly designed, narrow, 2 piece side gear arrangement found in most OEM clutch sure-grips. This changed in mid year 1968, a half year before Chrysler discontinued the clutch sure-grip.