Disassembled to find PO had installed new half-shaft. Did not run axle nut up completely before staking. 1st gen legacy bearing is dual tapered roller (timken) in a single housing. The outer race is one piece and inner races are two piece. If the axle nut is not tightened completely, it will not pull the inner races together and properly preload the bearing.
The dual tapered bearing design is better than a dual ball path bearing (i.e. honda) as it has has a larger surface area (tapered roller) than a ball bearing and a wider bearing convergence angle. As such, legacy bearings should last a LONG time in comparison. If your car is all original, and you have less than 200k miles on it, make sure the "bearing noise" you are hearing is not worn tires....
PO had also separted lower ball joint during axle install. This ruined the boot due to picklefork. NOTE: Lower ball joint need not be separated to install new axle/halfshaft. Instead, remove caps on inner control arm bushings!!!
Bearing is not too hard to remove and replace, but you must have a press (or special tools).
A word on parts: DO NOT USE TIMKEN BRAND SEALS! These are metal cased single lip. Instead use SKF, original design and quality. DO NOT USE AUTOZONE AXLE NUT. These are made in China and are not accurate. Use only genuine Subaru or Beck Arnley.[/b]
Bearing Removal
- remove knuckle from car. things that must be removed or separated include: caliper, caliper bracket, rotor, splash shield, lower ball joint, 2x strut bolts
- using a 6" split bearing puller, install on the outer side of the hub and flush against the circumferential shoulder located on the housing. nice of subaru to cast that feature as it works perfectly with the 6" bearing puller.
- now take to the press and using two 4x4 blocks of wood (or whatever) to act as a riser, place assembly outer side down so bearing puller bridges across wooden blocks. this clearance is needed to give the wheel hub somewhere to go.
- using a driver smaller than id of inner bearing cone (1.25" diameter works), press against face of splined hub shaft until wheel hub drops out, then remove split bearing puller. note that the outer seal and bearing cone will still be attached to the hub shaft.
- now to remove cone from wheel hub. install the split bearing puller between the seal and the bearing cone. usinng the 4x4 blocks as a riser, place the assembly hub face down so bearing puller bridges across wooden blocks.
- using same drive previously used, press hub free of outer bearing cone.
- remove inner seal with a screw driver. note that it has a megaphone shaped face seal that presses against the face of the halfshaft.
- using standard inside snap ring pliers, remove the snap ring. i know the snap ring looks different than what you are used to, but standard snap ring pliers are what you use to remove it.
- remove the inner cone and save for use in removing the cup.
- position knuckle on press, inner side down. you will need to use a riser (about 1") to level the knuckle. in this position, it will be standing on two points, the tie rod arm and another portion of the housing. this works just fine, don't be scared.
- place the cone into the cup, and using a 2" diameter piece of bar stock, press against the cone. the cone will press against the cup and cause it to slide out the bearing bore. it may be a little tight. don't give up.
- clean knuckle bearing bore and wheel hub seal and shaft areas with kerosene.
- remove the new inner bearing cones from the outer cup and clean away the "protective" grease applied at the bearing factory. use kerosene as a solvent. DO NOT DROP THE CONES, THE CAGES ARE BRITTLE PLASTIC AND WILL CRACK! blow the kerosene away with compressed air, or just roll on a towel until it is gone. i assure you, timken does NOT pack enough grease for road use.
- pack the bearing by hand, smashing it under the edges of the bearing cage with the palm of your hand. for taper bearings, i use good old moly-sulfide "disc brake bearing grease" from STA-LUBE.
- go to your press, and using a piece of round steel (i used 3.25" diameter x 3" tall) as bottom support, place the knuckle outer side down onto it.
- next, apply a light coat of grease to the inner bore of the knuckle. the grease will help things press together easily.
- using the outer race or cup from the old bearing, press in the new cup all the way until it stops. don't worry, the old race won't get stuck in the bore. subaru is pretty good about their design work.
- reinstall the snap ring
- install a cone on the inner side of the knuckle.
- apply grease to the inner seal lip AND outer diameter, then using the old timken cup and a hammer, carefully tap the seal in until it is against the snap ring. CAREFULLY!!
- flip the knuckle over and drop in the other cone.
- Again, apply grease to the outer seal lip and the outer diameter. using only a hammer, alternately tap around the perimeter of the seal until it is flush with the face of the knuckle.
- smear a little grease on both wheel hub seal and shaft areas . again, the grease helps things press together.
- using the same piece of round steel used previously, place the wheel hub face down so that the steel is within the wheel studs.
- on top, place the knuckle outer side down onto the wheel hub shaft. this will place the hub shaft into the bore of the outer cone. next, find a socket or something that fits inside the inner seal, but is larger than the bore of the inner bearing cone (i used 2" diameter x 4" long).
- carefully align, the assembly and begin pressing. after the hub shaft has started, release the press pressure and get another bite (this helps eliminate the potential for misalignment). continue pressing until it suddenly becomes very stiff, then release the press pressure. note that you are pressing the inner cone against the outer cone and against the hub shaft in a sandwich. the hub will just slide in until its shoulder bottoms against the face of the outer cone.
- hold the knuckle in your hand and wiggle the wheel hub, making sure there is zero slop. if all is well, it's ready to go back on the car!!!