RSM Replacement Advice Needed

[Nicolas Moss]

Back when I bought my E36 M3, the original owner gave me a box of spare parts which included some new E46 rear shock mounts. I decided that a reasonable winter project would be to throw them on, even though I’ve never done it before.

I looked on-line and ordered parts that would probably be needed (nuts, gaskets, bump-stops, dust tube), got the parts last week, and this being a nice sunny day off, decided to tackle it.

I got the first shock off easy enough, but then, huh… the existing parts look different than expected.

Here is the rear shock:

Here is the mounting hardware that was on the car:

Here is what I’m putting on the car:

Here are my concerns:

1. The existing bump-stop is much smaller than the new one. Should I be using the ones that were on the car as they are still in good shape?

2. Is the dust tube just supposed to float up and down along the shock shaft (I see nothing to anchor it).

3. The existing top washer was not the convex stock washer. It covers the new RSM fairly well, but I’m worried that its not enough and will cut into the mount. Should I replace it with the stock piece?

Thanks for any advice!

[Nicolas Moss]

Hrm… the image tags aren’t fully working. Let me try again. Here is the new setup:

[Nicolas Moss]

Well, I’m an image failure it seems. They are on my Facebook timeline. Hopefully the curious can see them.

[Bill Richter]

Hi, Nick.

Did you change the privacy setting on the FB pictures to “public”? I’ve been bitten by that before…

[Nicolas Moss]

I made them public in my feed. Honestly, FB makes me feel really old.

Anyway, I figured out that the new dust tube “snaps” onto the new bump stops. In the process, I had to take the shocks out again. So I’ll be ordering new mounting nuts, and while I’m in there, I might as well get the proper washer for the top. At least I can do that with everything still installed.

It seems the lower cupped washer really is just a free floating “cap” for the bump-stop. The RSM sits directly on the lip of the shock rod. I’m getting pretty good at taking the shocks in and out.

[Bill Richter]

You’re not the only one who feels that about Facebook!

Glad you got it sorted out.

[Nicolas Moss]

So I’ve got it pretty much figured out that the convex washer on the bottom is the wrong one, so I’ve ordered both top and bottom washers as well as new nuts. The only thing I’m unsure of is the bump-stop being longer that what was on there. The rear suspension does seem to sit a bit lower than stock, so maybe what was there is harder rubber but shorter to allow for more shock travel before hitting the stop?

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