How to change your own wheel bearings - hydraulic press required

[chief tool]

After seeing a few people wanting to do their own wheel bearings, I decided to do a write up on how to do it....

This for people who dont mind purchasing a few more specialised tools, such as a hydraulic press. The one I used cost $149 on ebay, so its not out of reach by any means. The other thing thats required is a 3/4 socket set....why you ask, we'll get to that.

Here is the press I bought some time back, which is more or less a necessity if you insist on tying to fit parts off different cars into yours...which involves alot of disassembly and measurement....it also doubles as a useful maintenance tool to do wheel bearings, control arm bushes, wheel studs, gearbox bearings etc.



Here is the knuckle/hub assembly removed from the car



If its rusty like this one, use some WD40 or PR7 on it the night before to help the hub pres out



select a small pry bar to remove the seal



remove the seal



support the knuckle in the press using some ingenuity to make it level, and be able to take the force for the press



Better shot



Now, this is where a 3/4 inch socket set comes in really handy, as you'll need a few things to mate the press to the hub and bearings etc.



Here is what I mean, the 30mm socket is a perfect fit inside the bearing onto the end of the hub



There wasnt quite enough travel to get the hub all the way out without the wheel studs hitting the table, so after the hub was about halfway out I raised the knuckle on both sides with some 2x1 pine



The knuckle with the hub removed



Here is the hub, note the scoring from being driven around for a long time on a faulty bearing. Some times you can clean this up with 400 paper, but if the scoring is too deep you have to replace it....also when removing groves with 400 paper, you cannot remove too much metal, or it will be a sloppy fit in the bearing, it needs to be a tight press fit....any doubt toss it out.



remove the circlip



find a socket big enough to use to press the bearing out of the hub, this step is where you need the 12Ton rating of the press!



bearing is out



clean the inside of the knuckle bearing surface until all the black crap is removed, I use paper towel and WD40/RP7 until the paper towels are clean.



installation in part 2.....http://www.mx6.com/forums/1g-mx6-gen...cs-pt-2-a.html

[chief tool]

Followed on from part 1, here is the installation of the bearing :

Now to put it all back together :

hub with the scoring cleaned up



New bearing... I prefer to use the NTN (part no. 4T-CRI-0822) but these were unavailable at the time, so I tried this chinese product, which was about 2/3 the price, but made in Germany, using a Koyo part number! go figure (the Koyo part number is DU4272C)



Support the knuckle as shown, I used a 50mm socket, which fits perfectly in the recessed area where the seal fits



Put the new bearing in, and place a bearing plate on the top, to make sure it goes in straight, the socket on top wasnt really necessary, I used it as a spacer.



I pressed the bearing in until it was flush, which is as far as you can take it with the plate.



So I cleaned up the old bearing to use as a spacer to pres the bearing in the rest of the way



Here it is pressed in all the way



Dont forget to re install the circlip! I made the mistake of forgetting this once and had to press the hub back out, destroying a new bearing in the process, an $70 mistake.



Now, this is the bit that decides just how long the new bearing will last once its installed...you must apply the press load to the inside of the bearing only, not the seal, and not the outside....if you do you will damage it. I have even seen shops get this wrong.....
So I selected a socket that is just the right size to lean on the inside edge of the bearing.



To install the hub I sat it face down on an old brake rotor, a convenient way of support it to give clearance to the studs. I carefully placed the knuckle with bearing on top, trying to keep the bearing as close to horizontal as my eye can see.
Then placed the socket in position....the top socket was unnecessary and was only used as a spacer.



There it is....done, there should be no noise or sloppy movement now.



Now for the seal, ideally you would use a piece of pipe the right size to tap in the seal.... I didnt have one (its about 2 3/4") so I improvised with a hose clamp.....its strong enough to tap in the seal.



finally I put some high temp wheel bearing grease on the seal lip, and a little bit on the mating face, purely to offer a small amount of discouragement to any water that does get past the seal

[Zach]

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