Driveline Angle Adjustment
Driveline Angle Adjustment
NOTE: Some vehicles may exhibit a drive-away shudder or vibration under moderate to heavy acceleration from a stop, especially when heavily loaded or when towing a trailer. It is important to confirm how the vehicle is driven the majority of the time (loaded or unloaded), as adjusting the driveline angle may result in a shudder or vibration with the vehicle unloaded. This procedure should only be used to correct or improve a shudder or vibration that occurs only when the vehicle is loaded.
All Vehicles
NOTE: The driveline angle must be measured with the vehicle loaded to determine the amount of adjustment necessary to correct the condition.
1. Measure the driveline angle. Refer to Driveline Angle Measurement. Driveline Angle Measurement
- If the driveline does not have an optimum 3 degree operating range, proceed to the following adjustment steps using the parts listed in the table below.
F250/F350 2-Wheel Drive (2WD) Single Rear Wheel (SRW) and 3962 mm (156 inch) or 4369 mm (172 inch) wheel base, F350/F450 2WD Dual Rear Wheels (DRW) and 3962 mm (156 inch) or 4369 mm (172 inch) wheel base.
NOTE: The driveline angle on these vehicles can be changed by adding 1 degree or 2 degree pinion angle shims.
2. NOTE: To change the pinion angle.
Using a suitable jack to support the rear axle, remove and discard the 8 U-bolt nuts and the 4 U-bolts.
- Install a 1 degree or 2 degree pinion angle shim (thicker end of shim towards front).
F250 Four-Wheel Drive (4WD) SRW and 3962 mm (156 inch) or 4369 mm (172 inch) wheel base, all 4WD DRW and 3962 mm (156 inch) or 4369 mm (172 inch) wheel base.
NOTE: The driveline angle on these vehicles can be changed by adding 1 degree or 2 degree pinion angle shims or a 2" O degree spacer block.
3. NOTE: To change the pinion angle.
Using a suitable jack to support the rear axle, remove and discard the 8 U-bolt nuts and the 4 U-bolts.
- Install a 1 degree or 2 degree pinion angle shim (thicker end of shim towards front).
4. NOTE: To add a 2" O degree spacer block.
Using a suitable jack to support the rear axle, remove and discard the 8 U-bolt nuts and the 4 U-bolts and replace the existing spacer block with a 2" O degree shim.
F350 4WD SRW 4WD and 3962 mm (156 inch) and 4369 mm (172 inch) wheel base
NOTE: The driveline angle on these vehicles can be changed by adding 1 degree or 2 degree pinion angle shims.
5. NOTE: To change the pinion angle.
Using a suitable jack to support the rear axle, remove and discard the 8 U-bolt nuts and the 4 U-bolts.
- Install a 1 degree or 2 degree pinion angle shim (thicker end of shim towards front).
F350 SRW 4WD and 3962 mm (156 inch) or 4369 mm (172 inch) wheel base
NOTE: The driveline angle on these vehicles can be changed by adding 1 degree or 2 degree pinion angle shims or a 4" O degree spacer block.
6. NOTE: To change the pinion angle.
Using a suitable jack to support the rear axle, remove and discard the 8 U-bolt nuts and the 4 U-bolts.
- Install a 1 degree or 2 degree pinion angle shim (thicker end of shim towards front).
7. NOTE: To add a 4" O degree spacer block.
Using a suitable jack to support the rear axle, remove and discard the 8 U-bolt nuts and the 4 U-bolts and replace the existing spacer block with a 4" O degree shim.
All Vehicles
8. Install 4 new U-bolts and 8 new nuts. With the suspension at curb height, tighten the new nuts evenly in a cross-type pattern in 4 stages.
For F250 and F350 vehicles:
State 1: Tighten to 65 Nm (48 lb-ft).
State 2: Tighten to 130 Nm (96 lb-ft).
State 3: Tighten to 200 Nm (148 lb-ft).
State 4: Tighten to 265 Nm (195 lb-ft).
For F450 and F550 vehicles:
State 1: Tighten to 100 Nm (74 lb-ft).
State 2: Tighten to 200 Nm (148 lb-ft).
State 3: Tighten to 300 Nm (222 lb-ft).
State 4: Tighten to 400 Nm (295 lb-ft).
F250, F350 4WD vehicles with SRW and 3962 mm (156 inch) or 4369 (172 inch) wheel base
9. If the shudder or vibration condition still exists, replace the center bearing support bracket with the part listed in table to raise the center bearing support height. For additional information, refer to the Driveshaft-Exploded View. Diagrams
10. NOTE: Once a new center bearing support bracket has been installed, a shudder or vibration may occur when the vehicle is unloaded. Shims can be used to lower the center earing support and minimize this condition. Up to 3 shims (per side) may be installed between the center bearing support bracket and the center bearing support carrier bracket. The center bearing support bolts must be replaced using the part listed in the table or new grade 5 bolts (7/16 inch x 14). The bolts should be long enough to extend at least 3 threads past the nuts.
Measure the driveline angle again. For additional information, refer to Driveline Angle Measurement. Driveline Angle Measurement
- If necessary, remove and discard the 2 center bearing support bolts and install shims to lower the center bearing support.
- Install 2 new bolts and tighten to 70 Nm (52 lb-ft).