Rubicon Express RE8003 - Manual (Page 3)

PHOTO 5
TROUBLESHOOTING
Rear driveline:
Acceleration vibration: Caused by the pinion being too high in relation to
the transfer case output shaft. Adjust lower control arm to lower pinion
accordingly.
Deceleration vibration: Caused by the pinion being too low in relation to
the transfer case output shaft. Adjust lower control arm 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 usually
be cured on 3.5” lifts with a transfer case drop kit. Note that pinion
adjustment may also be required - see acceleration and deceleration
vibration troubleshooting above. For best performance, consider a slip
yoke eliminator (SYE) kit and CV drive shaft (note that upper rear
adjustable control arms will be required for adjusting pinion angle for CV
type 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.
High speed wobble:
This is fairly common with y-type steering on lifted ZJ'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.
RI8003 Page 3 of 3