Mazda Trucks 1972-1986 Repair Guide

Wheel Bearings

Print


CAUTION
Brake shoes contain asbestos, which has been determined to be a cancer causing agent. Never clean the brake surfaces with compressed air! Avoid inhaling any dust from any brake surface! When cleaning brake surfaces, use a commercially available brake cleaning fluid.

ADJUSTMENT



See Figures 1, 2, 3 and 4

Click image to see an enlarged view

Fig. Fig. 1: Checking bearing axial play



Click image to see an enlarged view

Fig. Fig. 2: Checking the bearing for smoothness of rotation



Click image to see an enlarged view

Fig. Fig. 3: Checking rotational force using a spring scale



Click image to see an enlarged view

Fig. Fig. 4: Adjusting rotational forcetighten or loosen the hub nut until a reading of 1.3-2.4 lbs. is attained

  1. Raise and support the front end on jackstands. Check both the bearing axial play and the ease and smoothness of rotation. Axial play should be 0; the wheel should rotate smoothly, with no perceptible bearing noise.
  2.  
  3. Remove the wheel. Remove the brake drum or disc brake caliper. Suspend the caliper out of the way. Don't disconnect the brake line.
  4.  
  5. Attach a spring scale to a wheel lug.
  6.  
  7. Pull the scale horizontally and check the force needed to start the wheel turning. The force should be 1.3-2.4 lbs. If the reading is not correct, proceed.
  8.  
  9. Remove the grease cap and cotter pin.
  10.  
  11. Tighten or loosen the hub nut until the correct pull rating is obtained.
  12.  
  13. Align the cotter pin holes and insert a new cotter pin. Replace the grease cap and wheel.
  14.  

REMOVAL, REPACKING AND INSTALLATION



See Figures 5 through 23

Click image to see an enlarged view

Fig. Fig. 5: Exploded view of front hub components with drum brakes



Click image to see an enlarged view

Fig. Fig. 6: Exploded view of front hub components with disc brakes, through 1984



Click image to see an enlarged view

Fig. Fig. 7: Exploded view of 1986 front hub components



Click image to see an enlarged view

Fig. Fig. 8: To repack the front wheel bearings, pry off the dust cap ...



Click image to see an enlarged view

Fig. Fig. 9: ... remove the cotter pin ...



Click image to see an enlarged view

Fig. Fig. 10: ... and the nut lock ...



Click image to see an enlarged view

Fig. Fig. 11: ... then loosen and remove the adjusting nut and flat washer ...



Click image to see an enlarged view

Fig. Fig. 12: ... next, loosen and remove the caliper bracket-to-steering knuckle bolts ...



Click image to see an enlarged view

Fig. Fig. 13: ... pull off the complete caliper/bracket assembly ...



Click image to see an enlarged view

Fig. Fig. 14: ... and suspend out of the way with a piece of wire or rope



Click image to see an enlarged view

Fig. Fig. 15: Now grab hold of the rotor and carefully pull itbe sure to catch the outer wheel bearing as you pull the rotor off



Click image to see an enlarged view

Fig. Fig. 16: Pry off the rear grease seal to get to the inner wheel bearing



Click image to see an enlarged view

Fig. Fig. 17: With the seal removed, the inner bearing may be withdrawn from the hub



Click image to see an enlarged view

Fig. Fig. 18: Thoroughly pack the bearing with fresh, high temperature wheel-bearing grease before installation



Click image to see an enlarged view

Fig. Fig. 19: Apply a thin coat of fresh grease to the new inner bearing seal lip



Click image to see an enlarged view

Fig. Fig. 20: Use a suitably sized driver to install the inner bearing seal to the hub



Click image to see an enlarged view

Fig. Fig. 21: Driving out the bearing races



Click image to see an enlarged view

Fig. Fig. 22: Thoroughly pack the bearings with grease



Click image to see an enlarged view

Fig. Fig. 23: Pressing the seal into placea block of wood and a hammer can also be used

Sodium-based grease is not compatible with lithium-based grease. Read the package labels and be careful not to mix the two types. If there is any doubt as to the type of grease used, completely clean the old grease from the bearing and hub before replacing.

Before handling the bearings, there are a few things that you should remember to do and not to do.

Remember to DO the following:


Remove all outside dirt from the housing before exposing the bearing.
 
Treat a used bearing as gently as you would a new one.
 
Work with clean tools in clean surroundings.
 
Use clean, dry canvas gloves, or at least clean, dry hands.
 
Clean solvents and flushing fluids are a must.
 
Use clean paper when laying out the bearings to dry.
 
Protect disassembled bearings from rust and dirt. Cover them up.
 
Use clean rags to wipe bearings.
 
Keep the bearings in oil-proof paper when they are to be stored or are not in use.
 
Clean the inside of the housing before replacing the bearing.
 

Do NOT do the following:


Don't work in dirty surroundings.
 
Don't use dirty, chipped or damaged tools.
 
Try not to work on wooden work benches or use wooden mallets.
 
Don't handle bearings with dirty or moist hands.
 
Do not use gasoline for cleaning; use a safe solvent.
 
Do not spin-dry bearings with compressed air. They will be damaged.
 
Do not spin dirty bearings.
 
Avoid using cotton waste or dirty cloths to wipe bearings.
 
Try not to scratch or nick bearing surfaces.
 
Do not allow the bearing to come in contact with dirt or rust at any time.
 

  1. Raise and support the front end on jackstands.
  2.  
  3. Remove the wheel.
  4.  
  5. Remove the grease cap, cotter pin, hub nut and flat washer.
  6.  
  7. On trucks with disc brakes, remove the caliper and suspend it out of the way without disconnecting the brake line. Slowly pull the hub from the spindle, positioning your hand to catch the outer bearing.
  8.  
  9. Remove the spacer, inner seal and inner bearing. Discard the seal.
  10.  
  11. Thoroughly clean the bearings and inside of the hub with a nonflammable solvent. Allow them to air dry.
  12.  
  13. Inspect the bearings for wear, damage, heat discoloration or other signs of fatigue. If they are at all suspect, replace them. When replacing bearings, it is a good idea to replace the bearing races as a set, as bearings do wear the races in a definite pattern which may not be compatible with new bearings.
  14.  
  15. To replace the races, carefully drive them out of the hub with a drift.
  16.  
  17. Coat the outside of the new races with clean wheel bearing grease and drive them into place until they bottom in their bore. Make certain that they are completely bottomed! A drift can be used as a driver, if you hammer evenly around the rim of the race and are very careful not to slip and scratch the surface of the race. A driver made for the purpose is much easier to use.
  18.  
  19. Pack the inside of the hub with clean wheel bearing grease until it is flush packed.
  20.  
  21. Pack each bearing with clean grease, making sure that it is thoroughly packed. Special devices are sold for packing bearings. They are inexpensive and readily available. If you don't have one, just make certain that the bearing is as full of grease as possible by working it in with your fingers.
  22.  
  23. Install the inner bearing and seal. Drive the seal into place carefully until it is seated.
  24.  
  25. Install the spacer and the hub on the spindle.
  26.  
  27. Install the outer bearing, flat washer and hub nut.
  28.  
  29. Adjust the bearing as explained above.
  30.  
  31. Install the nut cap, cotter pin and grease cap. Install the wheel.
  32.  

 
label.common.footer.alt.autozoneLogo