SavageSun4x4 Expeditions

Setting the Rear Pinion angle on your Jeep to remove acceleration and deceleration vibrations.

Tools required:
Wheel chocks, 4
Straight edge
Angle meter
Small jack (OEM Jeep jack is fine) w/wood block about 4x4 6" long

1) With your rig in street position (wheels on the ground, transmission in neutral, DS attached, emergency brake OFF, FRONT wheels chocked in FRONT, REAR wheels chocked in the REAR)

2) Using a small screw or hydraulic jack and a wood block (I use a piece of 4x4 about 6 in long), place the jack under the pinion nose using the wood block. The jack adjustment handle should be facing towards the front of the jeep

Raise the pinion nose enough to release the strain on the adjustable control arms, then remove them by removing one end. If the bolt is too tight to remove try making small adjustments to the jack to take the pressure of the bolt.

3)* Using an angle meter (Sears, Harbor Fright, Home Dept etc, about $10) place it on lower portion of the DS as close to the pinion u joint as possible

4) Slowly raising your pinion nose and using the straight edge to check the DS-pinion u joint angle, you will want the pinion-DS angle to be between 1.5 - 2.5 degrees down from zero.

If on acceleration you get minor vibes then you will want to LOWER the angle a bit more, adding about 1 degree at a time until the vibes stop. If you get vibes on deceleration then RAISE your angle 1 degree at a time until the vibes go away

Use the straight edge and placement of the angle meter on the DS and 'flat' side of the pinion u joint to ascertain the minus 2 degrees +/- .5 degrees.

5) Adjust the ACA to the length required to freely insert the CA bolts.

Test drive noting any vibes on accel/decell and readjust as needed

*3) The angle meter will give you your total pinion angle up from zero. Angles beyond 16 degrees can lead to pinion bearing oil starvation and possible failure. To solve this install a pinion bearing saver.