Rear wheel bearings

[jcwhy]

Any words of wisdom for replacing the rear wheel bearings? I don’t plan on DIY without getting the proper tools/bearing puller. Not sure if it’s something I could rent locally ( Autozone, Napa, etc). Simple enough if I can get get the proper tool.

Thanks all.


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[fo3]

I haven't done it myself (I farmed this out along with rtabs and subframe bushes when I was busy moving house). But I do remember reading up on it in the DIY subforum years back when I considered DIY.
https://www.bimmerforums.com/forum/s...el-bearing-diy

There's also a vid out there that makes it look pretty straight forward if you have the right pullers and special tools. https://www.youtube.com/watch?v=tTYRZfGe8Kc

[moroza]

I've never done it in the car, always removed the trailing arm and did it in a press. YMMV with rental tools.

Remove axle. Remove inner hub flange lockplate. Set handbrake, remove collar nut. Using a press, puller, or slide hammer, pull the outer flange out, likely with half of the bearing inner race still attached. If that's the case, cut a notch in the race (carefully, to avoid cutting the hub) and whack it with a cold chisel until it splits, then remove. Remove the snapring holding the rest of the bearing in the trailing arm. Press the bearing out. Press the new one in, making sure to press only on the outer race. Reinstall snap ring. Press outer hub into the bearing, making sure to press against the inner race only, and do not use impact. Specifically, DO NOT use the collar nut to draw the outer hub in; this will likely result in destruction of the nut and hub, and taking it apart again likely results in destruction of the bearing as well. Only when the outer hub is seated fully in the bearing can you install the inner hub and then the nut. My experience has been that using the collar nut to seat the inner hub is ok. On paper, you need a new lockplate. I reuse them at discretion.

Note that 525i sedans (not wagons) used different bearings than all other US E34.

Some reference: https://www.bimmerforums.com/forum/s...l-bearing-help

[eddycooper]

This thread has a decent description of the job: https://www.bimmerforums.com/forum/s...el-bearing-diy

Make sure you have the right tools before you start. I bought this puller set, which almost has the right pieces: https://www.amazon.com/Universal-Sle.../dp/B00QMZJB9I. I had to get one sleeve that's just a bit larger than the biggest one in the kit in order to push out the outer race. If you've already got your replacement bearings then you can measure them directly.

While you're there, there are a couple of other jobs that you could consider since they are otherwise a lot more work:
- E-brake cables and/or e-brake mechanisms
- Brake dust shields if they're in bad shape

[jcwhy]

Think I have everything at this point.

Thanks for the guidance.

~j

[jcwhy]

I have everything disassembled and ready to extract the old bearing. The OD of the bearing is 80mm so need a bushing of this size or slightly smaller to rest against the outer race. The OD of the outer part of the trailing arm is 93mm so I'm thinking I need a sleeve with ID 93mm or slightly larger. This sleeve will sit on the outside of the trailing arm while cranking down the press. So far, I haven't found one but will keep looking. Do I have this right?

Then comes the question of inserting the new bearing. The inner portion of the trailing arm has an opening that's slightly larger than 80mm (~81.5mm). So, to pull in the new bearing I'm thinking I need another sleeve to fit in this opening for pulling in the bearing? Not sure if I'm making sense but just trying to understand the best approach to support the inner portion of the press while cranking down to pull in the new bearing. It's not even a flat surface so my concern is get a good fit so the bearing pulls in properly.

I'd love to have that pneumatic tool shown in the YouTube video. https://www.youtube.com/watch?v=tTYRZfGe8Kc

- - - Updated - - -

I discovered I needed to lower the exhaust to get adequate access to the left side for removing the spline nut with an impact. Just wasn't enough room.

[eddycooper]

For a "receiving cup" to pull the bearing out into, I bought a small piece of 3.5" tube (not pipe) with 0.125" wall thickness. The ID is 82.5mm, just a bit bigger than the bearing. It stacked onto the bearing housing (slightly different setup than you're planning for, it sounds like).

[demetk]

To pull the stub axle in I used this contraption.

[jcwhy]

Looks like it should to the trick. Just need to find the correct diameter pipe.

So you used the inner race from the old bearing to mate exactly with the new inner race in the hub?

[demetk]

Looks like it should to the trick. Just need to find the correct diameter pipe.

So you used the inner race from the old bearing to mate exactly with the new inner race in the hub?

Yes, I used the old race. The pipe is a from a home depot lolly column.

[jcwhy]

Thanks for the info.

What did you use for the threaded adapter to the axel?

Cannot locate a m27 x 1.5 coupler anywhere.

[demetk]

I used a plumbing coupler with the wrong thread but it did grab a couple of threads on the axle and that was enough to pull with. Subsequently I did locate a bunch of nuts with the correct thread. Let me know if you'd like one.

[jcwhy]

Demetk - sent you a PM about this

Thanks.


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[eddycooper]

I figured I would add to this thread. I found a somewhat simpler way to pull the inner hub into the (new) bearing. I 3d-printed some rings that allow you to use the big hub nut to pull it in, 10mm at a time. The rings are 56mm OD, 44mm ID, and 10mm tall. They will push on the inner bearing race only if aligned correctly (not the bearing seal).

Put a ring onto the inner race and then tighten the nut all the way down. Take the nut back off, add a ring, and tighten again. If I recall correctly, it took 4 of these stacked to get the inner hub fully into the bearing. To make this work well, I used scotchbrite pads on the inner hub to make it smooth and minimize friction before assembly. And of course a bit of grease to make it slide better. The PLA plastic I used held up fine to the compression that it saw.