Rear Wheel Bearings
Back Z on ramps front wheels blocked
Jack diffy and remove wheel
Unbolt 1/2 shaft with two 14mm wrenches (car in neutral and no brake so that wheel can be rotated)
Put wheel back on for safety but keep jacked so that wheel can be rotated (no need to tighten lug nuts... snug is fine)
Get the secret weapon (note: I stacked two cutting disks as they are so frail! This helped after I broke 4!!!!)
Cut peened nut's top (cut off full 360°) Rotate wheel as you do it. Bad photo but you can see metal dust on strut tube!
Make sure you have no gas leaks!! Lots of sparks!
Now for the trick! Get your 27mm socket and shaft on the wheel like this (above)
Not like this!!!!
Wrong!!! With the socket shaft so high, it will hit the fuel take above when pulled up! It is important that it is as low as possible.
AND THERE IS NO SLOP! LIFT THE SOCKET'S DRIVE SHAFT TO MAKE SURE IT IS NOT HERE WHEN THE FORCE IS APPLIED TO THE NUT.
Lower the car and ensure socket and shaft are in correct position (2nd photo above)
Stick your breaker bar on the socket driver shaft and lift up to break the nut free. Once you crack it, stick a ratchet on the 27mm nut and get a smaller breaker bar (see the black one by the flood light!)
Also note the snake light wrapped around the differential tower (that is the funny silver globe )
Also take a look at the big breaker bar relative to the gas tank. Now you should understand my tip above... you only have a few degrees of turning motion!
Hard Job #1 is done with no pain! See the cut off upper flange of the nut and Mr. 27!
Here is my home made slide hammer which pulled harder and allowed my full weight to pull! (see the lights from the night before)
Here is my trusty brass drift and the tow points from my Rav4.
Here is the home-made "basher". A threaded rod, a hook (for the brass drift) and the aluminum hub. I could pull the hub with two hands and take a full step. It would almost rock the car off the jack stand! Sure hurts the elbows and ears!!
I ended up renting a slide hammer and breaking it! I then got mad, fixed the hammer and heated up the rear flange for 5min.
After 20 hit's the assembly cam apart!
See the rusty spline... that and the inner bearing is what causes the trouble above.
The "mustard thingy" is the spacer coated with old grease.
The outside bearing is bound very well to the axle.
Here is the back side that pops off. The companion flange and the washer that fits between the peened nut and companion flange.
Pry out the oil seal. It is rubber with a steel inner structure.
Inner bearing (still greased up)
Inner bearing waiting to be pushed out. End of a 27year ride!.
Tap Tap Pop!
Here is axle after I had outer wheel bearing pressed out by a friend in the club (thanks Don)
I also used a "scotch brite" pad to clean it up.
Wrap the axle and put in the freezer for 2 hours. (Some use a C02 fire extinguisher to cool it)
Lets look at the parts:
Inner Bearing (other side) Identical
Outer Bearing (with built in seal) This side faces away from car towards lug nuts.
Outer Bearing (Other Side)
Washer between companion flange and lock nut
Companion flange (1/2 shaft side)
Companion flange (1/2 shaft on left, hub on right) Grease seal covers silver right side.
Companion flange, grease seal/hub side
Lock nuts (ZX type) No need to peen!!!!
New Bearings (Outer on left and inner on right) The red seal faces the outside world.
Wrap the outer bearing in a balloon, suck the air out and tie. Weird hey?
Place bearing in boiling water. Do not let bearing touch bottom. This keeps temp at 100°C
Dry off and open after 4 min.
Get axle from the freezer and apply anti-seize where new bearing will slide.
Pop hot bearing on with red seal down towards lug nuts.
If bearing won't slide on then persuade it!
Here is a tool Don loaned me. It worked great for bracing bearing while I pounded axle.
Note the condensation on the cold axle. Wipe it off!
Note the slight space between the flange and bearing. Don't worry, it will be pulled together.
Pack in grease. Force it in with finger and turn bearing each way. Do this for a couple of minutes.
Turn on side and rotate flange to work in grease. Go up one photo and pack more then tilt on side and spin. Do this 4 times to work in grease.
Grease it up!
Grease the inside of the spacer
Clean hub where bearing will be pressed. Outside (shown above) and the inside (lurking in hole)
Flush the dirt out. Catch drippings with shop towels or bucket.
Clean room on the driveway gravel. All ready to reassemble!
Note spacer on axle.
Grease up the inner bearing. Look at this side!
Now look at the other. Only some grease is peeping through! Keep working from the other side then apply grease on this side.
Remember to spin the bearing in both directions.
Place the new inner bearing in place. Take time to line it up!
Here is the old inner bearing. It will be used as a "press".
Clean it then grease it up to prevent the old grease from contaminating the new bearing.
Here are the two bearings in place after tapping with a hammer. The new bearing is deep inside. The old bearing "press" can be removed easily.
All set in place!
Grease other side of bearing and cavity.
Grease the axle with spacer.
Push axle in place.
Stick companion flange on hub and tighten with old nut to pull bearings into place.
Remove the companion flange then grease the inner seal (ignore the fact it s on the companion flange... hey we all make mistakes :)
Put the inner grease seal in place. (Tap with hammer)
Stick on the companion change then the washer.
Put nut in place and tighten. Torque between 186 and 220 ft-lbs.
My torque wrench failed so I just tightened it with a 4' breaker bar.
Turn wheel to feel for problems. If ok then:
Put E-brake on.
Install 1/2 shaft
Drop wheels to ramps
Drive down off ramps
A great post from Zcar.com:
Date: Jun 19, 2001 2:40pm
Thanks to everyone who gave me advice or just moral support. I have replaced my rear wheel bearings on my 78 280z. It wasn't really that bad. I'll run through it just in case someone is considering it. I still have some noises in the rear end so I'm not done searching yet. I'm going to jack it up and run it to see if it is from the hub or differential or drive shaft or what.
1) First you need to get your replacement bearings. Inner and outer. Also buy the grease seal that goes next to the inner bearings.
2) Next, get you a 27 mm socket and a breaking bar. A 48" piece of galvanized 3/4" pipe worked well for me.
3) Go to your local auto zone or whatever and rent a slide hammer and a slide hammer adapter. You will bolt the adapter on the wheel studs while you loosen and tighten the nut.
4) Put the car on jack stands, remove the wheel, and remove the brake drum.
5) Remove the four bolts that hold the half shaft to the stub axle and tie the half shaft up out of the way (on a coil spring or something).
6) Now you see the 27 mm nut. It has been flattened on two sides to hold it in place. Bolt the slide hammer adapter to the wheel studs and use something (I used a 4-way lug wrench) between the adapter and the ground to keep it from turning. Use your socket and breaking bar and remove the 27mm nut. With a 4' bar, it isn't that hard.
7) Pull the nut off and the washer behind it. Then use your slide hammer and pull the stub axle out. The plate that the half shaft bolts to probably just fell off too. Save all your pieces and keep them grouped together if you are working on both sides of the car. You will have the half shaft mounting plate, 27mm nut, washer, bearing spacer, stub axle.
8) Use a screwdriver (I used a pair of channel locks) to remove the grease seal that is on the inside of the hub. It is now holding the inner bearings in. Then use a drift, socket, or something to knock out the inner bearings. You knock them out from the wheel side.
9) Use a gear puller or find someone with a press to remove the outer bearings from the stub axle.
10) Clean everything up. The stub axle, inside the hub, etc. I used brake cleaner and a rag. Then take some emory cloth and polish the areas on the stub axle where both bearings will go. Also, polish inside the hub. These areas should now be shiny clean like they were brand spankin new.
11) Pack all your new bearings with Mobil 1 synthetic grease. Put your Outer bearings in the oven on Warm. Put your stub axle and inner bearings in the freezer.
12) Have a beer. You have been working hard.
13) Get your outer bearings and stub axle. The outer bearings should slide right on the stub axle. Make sure the seal in the bearings faces the wheel studs. Grease it all up and put it in the freezer. Don't get any grease on the pork chops! Your wife won't like it much.
14) Get your inner bearings from the freezer and install them in the hub. Knock em all the way in. Pack your grease seal with grease and install it. Knock it flush with the hub.
15) Get your stub axle from the freezer. Put some grease in the cavities inside the hub. Make sure you have your bearing spacer on and install the stub axle into the hub. Knock it all the way in.
16) Install the half shaft mounting plate on the back. Put on the washer and the 27mm nut. Torque it back to where it was before you removed it. You should be able to line up the flat spots on the axle with the marks on the nut. Use a chisel or something to flatten it out again in those two spots.
17) Holy Cow! Bolt your half shaft back up, put your drum on and your wheel and your finished. You probably ought to change clothes and wash your hands.
I think that's it. I may have forgotten something but heck, that is why you have your manual :). The manuals are pretty vague about all this though. They do say that you are supposed to torque the 27mm nut between something like 180-230 ft/lbs of force. These may not be the exact numbers. Also, they say that you can take a spring gauge and try to turn the hub from the wheel stud and it should take 2 lbs or force or less to turn it. You should adjust the 27 mm nut within the required torquing range until it takes 2 lbs or less to turn the hub.
I didn't do any of the torquing stuff. I just guessed by torquing the nut until it was back to where it was before I took it off.
Hope this helps somebody.