Rubicon Express RE6130 - Manual (Page 4)

RI61116130 Page 4 of 4
LIFT KIT TROUBLESHOOTING
Rear driveline:
Acceleration vibration: caused by the pinion being too high in relation to the transfer case output shaft. On leaf sprung vehicles, install axle shims to lower pinion accordingly.
Deceleration vibration: caused by the pinion being too low in relation to the transfer case output shaft. On leaf sprung vehicles, install axle shims to raise pinion accordingly.
Slip yoke vibration: caused by excessive angle on the transfer case slip yoke. Very common on vehicles with 2” or more of lift. This can sometimes be cured on 4.5” lifts with
a transfer case drop kit and an RE1822 high travel slip yoke (84-95 XJ’s only since later XJ's already have the high travel slip yoke and may instead require an SYE and CV
drive shaft). Note that pinion adjustment may also be required- see acceleration and deceleration vibration troubleshooting above. For best performance, install a slip yoke
eliminator (SYE) kit and CV drive shaft. Adjust pinion so it is 2 degrees below parallel with CV drive shaft (see acceleration and deceleration vibration troubleshooting above).
A transfer case drop kit can usually be omitted with a CV drive shaft.
Drive shaft bind (84-95 XJ's): condition of interference between slip yoke and tube yoke. A high travel slip yoke (part #RE1822) may remedy this. Later XJ's already have the
high travel slip yoke and may instead require an SYE and CV drive shaft (see above slip yoke notes).
High speed wobble:
This is fairly common with y-type steering on lifted XJ's. It is a condition where front tires will shimmy after hitting a bump. Avoid bias ply tires and wheels with excessive
offset. Check for worn or loose parts. In most cases a reduction of positive castor will eliminate this condition. A good rule of thumb is minimum factory caster and
maximum factory toe in. Note that lift heights increased with coil spacers (or taller coils) may exhibit wobble that cannot be corrected with alignment.
Bump steer:
Caused by improper relationship of drag link and track bar. To correct, center axle again following the instructions supplied with the track bar. Next determine the neutral
position of the steering wheel. Adjust the drag link to center the steering wheel.