Drive/Propeller Shafts, Bearings and Joints: Adjustments

DRIVELINE ANGULARITY ADJUSTMENT
1. Measure the ride height (X) between the top of the axle tube and the bottom of the frame rail. The vehicle must be in the curb weight (unloaded) condition. Find the recorded ride height. The specified driveline angles correspond to the measured ride height.
2. Check the driveline angles (using a Pinion Angle Level Gauge T68P-4602-A.)

NOTE: Driveline angles up to 12 degrees can be inspected using Pinion Angle Level Gauge T68P-4602-A or equivalent. An adjustable bubble protractor is necessary for driveline angles over 12 degrees. All angles should be read within 0.5 degrees with the tool or with the protractor contacting a clean, flat surface.





a. If using Pinion Angle Level Gauge T68P-4602-A or equivalent, place the tool directly behind the rear axle area (A) on regular cab vehicles. Place the Pinion Angle Level Gauge T68P-4602-A or equivalent behind the cab area (B) on Cab-Plus vehicles.
b. Calibrate the Pinion Angle Level Gauge T68P-4602-A or equivalent by taking the average reading from both sides of the vehicle.





c. The angle of the component is measured by mounting Pinion Angle Level Gauge T68P-4602-A or equivalent to the bearing cap of the spider.
3. Check the driveline angles (using an adjustable bubble protractor.)

NOTE:
- All angles should be read with the protractor contacting a clean, flat surface.

- The engine angle can be measured off the bottom of the starter motor if the transmission obstructs the protractor.





a. If using a protractor, place the protractor directly behind the rear axle area (A) on regular cab vehicles or behind the cab area (B) on Cab-Plus vehicles to determine the frame angle.





NOTE: The protractor cannot be zeroed relative to the frame. The measured frame angle reading will have to be added/subtracted from the measured component angle reading before comparing to the specification.





b. Check the engine angle by rotating the propeller shaft until one yoke ear is parallel to the floor. Place the protractor flush against the yoke ear.

NOTE: Make sure the protractor is not resting against any portion of the propeller shaft assembly.

c. Record the angle reading.
d. To determine the engine angle reading subtract the angle reading from the frame angle reading.

NOTE:
- The engine angle reading should not differ from specification by 1 degree or more.

- Check the propeller shaft and pinion angles with the engine angle within specification.





e. Check the propeller shaft angle by placing the protractor on the propeller shaft.

NOTE: The plane surface of the protractor should be flush against the bottom surface of the propeller shaft and parallel to the floor.

f. Record the angle reading.
g. To determine the propeller shaft angle subtract the angle reading from the frame angle.





h. Check the axle pinion angle by placing the protractor flush against two rear axle cover retaining bolts.
i. Record the angle reading.
j. Subtract the angle reading from 90 degrees.
k. Record the adjusted angle reading.
l. To determine the pinion angle, subtract the adjusted angle reading from the frame angle.