Rear wheel bearing

Put the rear up on jack stands and remove the wheels and brake drums. Then unbolt the rear differential cover and drain the gear oil. Then, you remove the pinion securing bolt. DO NOT ROTATE THE WHEELS AS THIS CAN CAUSE THE PINION GEARS TO FALL OUT. Push the rear axle shaft inward toward the vehicle and remove the "C" clip that secures the axle to the pinion gears. Then pull the axle shaft outward and out of the axle housing. Inspect the axle shaft for scuffing and excessive wear on the place where the wheel bearings rest. If there is excessive wear, you can use a "repair bearing", which is modified to install so it runs on an unworn part of the axle shaft. Otherwise a regular replacement bearing is fine. You need a slide hammer removal tool to extract the old bearing from the axle housing, and a bearing install tool to insert the new one without damage. Once the new bearing is in, reinsert the axle shaft, secure with the "C" clip, and pull outward to latch the "C" clip into its recess. Install the pinion bolt. Reinstall the differential cover with appropriate gasket or sealer. Fill differential with approved gear oil in the recommended amount. Ensure that if the rear is a positraction rear end there may be an additive required to the gear oil for proper operation.

Pull the rear axles, remove axle seal. There is a special bearing removal tool that attaches to a slide hammer. Insert tool thru center of bearing and use slide hammer to pull out. Use old bearing against new bearing and tap in with hammer

pull wheel remove grease cap undo carter key remove nut pull off rest of hub take bearings frt and rear out of hub clean old grease from bearings check bearing for defect install in revers order remender to install new grease in new bearings lots of grease and u will need new seals for same front and rear

remove this items in this order(rear disc):
-remove rear wheel(the side you are replace)(19mm socket)
-remove brake caliper with cailper bracket(14mm socket)
-remove brake disc
-remove metal cover hub/bearing assembly with flathead screwdriver
-remove 36mm nut behind metal cover.
-pull hub/bearing assembly out.
note:sometime the inner side of bearing stay on knuckle and you have to pry it out pry bar. check old bearing vs new bearing and you'll see the different. Don't reuse any parts of the old bearing.
-install new hub/bearing

Replacing outer wheel bearings on a solid axle rear end is a moderately involved operation.

The rear axle cover has to come off so that you can remove the C clips to allow the actual axle to come out. Once out, a bearing puller is needed to remove the old bearing, and a bearing installed may be needed to drive in the new one.

If this sounds out of your comfort zone, a shop should charge $200-$300 to make the repair.

Sodium based grease is not compatible with lithium based grease. Do not lubricate the wheel bearings without first thoroughly cleaning all old grease from the bearing. Use of incompatible bearing lubricants could result in premature lubricant breakdown.

1. Raise and support the vehicle safely.
   
2. Remove the wheels.
   
3. Remove the brake drum or brake disc.
   
4. Remove the hub grease cap.
   
5. Remove the cotter pin retainer, adjusting nut and flatwasher from the rear wheel spindle. Discard the cotter pin.
   
6. Remove the outer bearing and cone assembly.
   
7. Remove the rear hub from rear wheel spindle.
   
8. Using Seal Remover (TOOL-1175-AC) or equivalent, remove and discard the oil seal.
   
9. Remove the inner bearing cone and roller assembly.
   
10. Clean the inner and outer bearing cups with solvent. Inspect the bearing cups for scratches, pits, excessive wear and other damage. If the bearing cups are worn or damaged, remove them using a Bearing Cup Puller (T77F-1102A) or equivalent.
    

To install:

1. Throughly clean old grease from the surrounding surfaces. If a new hub assembly is being installed, remove the protective coating using degreaser.
   
2. If the inner or outer bearing cups were removed, install replacement cups using Bearing Cup Replacer (T73-1202-A) or equivalent. Seat the cups properly in the hub.
   

If a bearing packer is not available, work as much grease as possible between the rollers and cages. Grease the cone surfaces.

1. Using a bearing packer, pack the bearing cone and roller assemblies with a premium bearing grease.
   
2. Place inner bearing cone and roller assembly in the inner cup. A light film of grease should be included between the lips of the new grease retainer.
   
3. Install the retainer with Hub Seal Replacer (T83T-1175-B) or equivalent. Be sure the retainer is properly seated.
   

Keep the hub centered on the spindle to prevent damage to the retainer and spindle threads.

1. Install the hub assembly on the spindle.
   
2. Install the outer bearing cone and roller assembly on the spindle.
   
3. Install the flat washer and nut. Tighten the nut to 18-23 ft. lbs. (24-31 Nm) while rotating the hub to set the end-play. Back off the nut and retighten to 18 inch lbs. (2 Nm).
   
4. Install the new cotter pin.
   
5. Install hub grease cap.
   
6. Install brake drum or disc.
   
7. Install the wheels.
   
8. Lower the vehicle.
   

A Front Wheel Drive Vehicle Can Have Two Types Of Rear Wheel Bearings: Serviceable Bearings, Or Nonserviceable, Sealed Bearings. When Sealed Bearings Fail, The Bolts Holding The Bearing And Hub To The Axel Or Control Arm Must Be Removed. When Installing The New Bearing Assembly, Torque The Bolts To Specifications.Some Manufacturers require The Use Of New Fasteners When Rear Bearings And Hubs Are Replaced.

When A Serviceable Wheel Bearing Is Used, The Bearing Can Be Disassembled And Packed With Grease.It Is Serviced Like A Front Wheel Bearing On A Rear-wheel-Drive-Car.

What year miata?

Yes it is as easy as it looks. If you had the tire off and figured out that it looks easy, you shouldn't have much problem.