User's Manual

Date of Origin – 02/01/08

HUB AND BEARINGS

HUB MAINTENANCE

Check wheel studs for good condition – no stripped threads – no bent or loose studs. Replace any

broken or bent studs or studs with damage to the threads. When a broken stud is replaced, the

stud on each side of it should be replaced at the same time. If more than two studs on the same

hub are broken, replace all of the studs.

WHEEL BEARING INSPECTION

Periodic inspection of wheel bearings and lubricants as well as regular lubricant changes are

necessary for good maintenance and maximum wheel bearing life. The hub and/or wheel assembly

must be properly cleaned to obtain optimum bearing life. This step also applies to field service.

When adding or checking oil level, make certain cap and plug are clean. This step will minimize the

possibility of dirt and road grime entering the system.

WHEEL BEARING ADJUSTMENT

1. Install adjusting nut so that pin on nut faces away from the hub.

2. Tighten inner nut to 200 ft. lbs. while rotating the hub in both directions.

3. Completely loosen the inner nut, then retighten to 50 ft. lbs. while rotating the hub in both

directions.

4. Loosen the inner nut ¼ turn. Do not include socket backlash in the ¼ turn.

5. Install the lock washer. If the hole in the lock washer is not aligned with inner nut pin, remove

the washer, turn it over and reinstall. If the washer hole is still not aligned with the pin, loosen

the inner nut slightly until the hole and pin are aligned.

Note: The washer may have to be reversed again with minimum loosening of the nut.

6. Install the jam nut; Torque to 300 ft-lbs.

7. Check the hub end play with a magnetic base and dial indicator.

a. Place the magnetic base and indicator on the end of the spindle. Touch dial indicator

stem to hubcap gasket face.

b. Slightly rotate the hub & drum in both directions while pushing inward until the dial

indicator reading does not change.

c. Set the dial to zero.

d. Slightly rotate the hub & drum in both directions while pulling outward until the dial

indicator reading does not change.

e. Read the end play from the dial indicator.

8. End play between .001 and .005 is acceptable.

a. If the end play is less than .001, loosen the jam nut; Repeat steps 1 through 8, and

retorque to 300 ft. lbs.

b. If the end play is greater than .005, increase the jam nut torque to 300 ft. lbs.

9. Repeat Steps 6 & 7 as necessary until the end play is within the acceptable range.

10.Bend tabs on lock washer over opposite flats of the jam nut.

BEARING LUBRICANT

The lubricant change interval depends on the type of lubricant used; oil or semi-fluid grease. Oil

levels should be checked as part of the daily inspection. Oil should be changed whenever seals are

replaced, brakes are relined, or at least every 12 months or 100,000 miles. Fill hubs with new oil to

the level indicated on the hub window using HD80-90W heavy duty oil with an API rating of GL-15 or

GL-4.

CAUTION! DO NOT overfill oil. Oil seal damage may occur due to excessive

internal pressure.