1992 Laredo, 6.5" lift on 33's, 4.56 gears, SYE, Rough Country lift. At 14 MPH there is a low speed vibration that goes away when I take the front drive shaft out. Had it rebuilt and balanced and the vibration is still there. Found my Tranny mount is toast. Could this be the problem?

 

How's your pinion angle on the front axle going to the font DS?

 

It should be fine I have had no problems in the past. It just started doing it.

 

just checked, the pinion needs to be rotated backwards......

 

Ahh, gotcha. So the pinion was angle too high up or too low? The front axle pinion should basically from a straight line with the DS. Pretty close anyway.

 

The Cherokee FSM says caster before pinion angle. If it's a DD, keep the caster at a factory angle and remove the front driveshaft until you need it.

If it's a weekend warrior, point the pinion straight up to the transfer case such that it forms a straight line with the driveshaft.

 

Run as much Caster as you can until you start getting vibrations from the excessive pinion angle then back off a degree or so.


From the FSM
VVVVV

NOTE: Changing caster angle will also change the
front propeller shaft angle. The propeller shaft
angle has priority over caster.