Interested in learning more about changing the wheel seals of your semi-truck? Depending on your experience level, it may be something you can do on your own without seeking the assistance of a specialist. However, we recommend that you do this at your own risk. If you’re not comfortable doing it yourself, give us a call and we’ll get your truck in the shop. If you’d like to give it a shot, here's how you can get the job done step by step.
On a level area, secure the vehicle using wheel chocks. Raise the wheel end off the ground and use a heavy-duty jack stand to stabilize the axle. Back off the slack adjustment and release the brakes. This is not a job for an impact wrench. Before ArvinMeritor adjusters can be backed off, a locking pawl mechanism must be pulled out or removed. Remove the wheel by unbolting it. To release the rusted link between the drum and the hub, use a heavy hammer, slip the drum off the brake shoes and set it to broadside down on the floor.
To prevent the threads from hammer damage, loosen the axle-flange nuts until they flush with a drive axle's bolt ends. Using a sledgehammer, repeatedly pound the middle of the flange until it separates from the hub. Remove the nuts from the axle and slide it out of the hub. Most flanges are now fastened with conventional lock washers and nuts. Conical (or cone-like) washers are used on certain to assist align the flange. This kind needs typically a lot more work to remove. For non-drive wheels, none of this violence is required. Simply remove the hubcap bolts and gently tap the cap loose with them.
Two big nuts (adjusting and jam) and at least one locking ring are used to secure specific hubs. Others feature a single cotter pin and nut. A unitized device is used to secure specific modern hubs. They may be removed using one or two big 3/4-inch drive sockets, which can be bought for as low as $30 at a decent parts shop. To remove or tighten wheel-end nuts, never use a hammer and chisel. This haphazard approach is dangerous and perhaps costly. Slide the hub out until the outer bearing is towards the end of the spindle after the bolts have been removed. Remove the bearing, then remove the hub and thread the wheel bolts into the holes in the brake drum.
Use a medium to big "crow's foot" pry bar to remove the seal. The inner bearing must be removed. Some seals need the removal of a worn sleeve from the axle shoulder. If you hammer standard (flat) wear sleeves, they will expand. Others with contamination protections may be pushed away with a powerful punch or drift. It would help if you never chiseled the sleeves since you can damage the surface underneath them.
In a cleaning solution, soak the hub, bearings, and hardware. Dry the pieces with pressured air and clean cloths after rinsing them with a new solvent. Never use high-pressure air to spin a good bearing. Clean any other components that may have been drenched in leaking oil thoroughly. Look for grooves, nicks, or further damage on the axle shoulder. Check the bearings and cups for symptoms of spalling, pitting, overheating, or wear, and replace them if necessary.
Polish any rough places on the axle shoulder or hub bore using emery cloth strips. Minor flaws may be filled using liquid metal or Permatex No. 1 hardening. Smooth the repairs with an emery cloth after they've dried. Repair sleeves or a hybrid seal/wear sleeve should be used to cover gouges that ring the shoulder. If a sleeve is required, cover the shoulder with a non-hardening silicone sealer, then use a heavy hammer and suitable sleeve tool to force the sleeve into place – flush with the shoulder's outer surface. Remove any remaining sealant.
SEAL IN PLACE. Place the hub on the brake drum (wheel bolts down) and thread the bolts through their holes. Make that the replacement seal is in good working order. Clean lubricant of the sort used in the wheel end should be applied to the inner bearing. Place the bearing in the cup it came in. Using a clean cloth, wipe the seal bore. The side of the seal that faces the bearing should be noted. Poke the end of a suitable driver (available from the seal manufacturer) through both the seal and the bearing. Squarely pound the seal into the bore until you hear a difference in the hammering sound.
Lubricate the outer bearing and place it on a clean cloth with the attaching hardware. Slide the hub onto the axle spindle with care until it lands on the shoulder. Make sure the hub is installed correctly. Remove it if it binds, and examine the seal for damage. With one hand on the hub, swiftly insert the outer bearing and tighten the big adjustment nut according to the specifications for that specific wheel end.
Manufacturers typically suggest using a torque wrench and dial indicator to adjust the bearing tension accurately. On the other hand, most mechanics depend only on a torque specification. When working on a classic heavy-duty axle with a double-nut fastening system, they'll revolve the hub while cranking down the adjustment nut to 200 pounds-feet. Then, while spinning the hub, they'll back off the nut a full turn and retighten to 50 pounds-feet.
Clean the hubcap or axle flange's mating surfaces. Install and tighten this last item using a fresh gasket or a sealant layer – never both. The tiny bolts on hubcaps should not be overtightened. While lubrication is injected through the vent-hole plug, non-driving hubs should be gently rotated. Raise the other end of the axle 6 to 10 inches with a drive hub, then wait for the oil to move from the differential to the wheel end. As required, replenish the differential.
And BOOM! Now you know how to change wheel seals. As the last step, you can replace the wheel and tighten the lug nuts to the manufacturers suggested ft-lbs. When an assistant provides air pressure, manually tighten the slack adjuster and verify its movement. To make sure the hub isn't leaking or overheated, drive 5 to 10 miles.
