Spindle Eccentric Bolt - BMW Substitute

[q20v]

*** Update - See Audi replacement part numbers in the posts below. You don't need to buy BMW parts! ***




Hey guys,

I found what appears to be a near identical replacement option to the rear spindle eccentric bolt (NLA).

The NLA bolt in question (Item 21 - 8A0 501 387 C)




I was looking at refinishing mine since they have a bit of surface rust, then thought to explore BMW options. After a rudimentary google search it occurred to me that I own a BMW and coincidentally have the same mental condition as I do with the Audis. Chronic Partswhore... quite serious, I should get checked out. Anyway, I had the BMW eccentrics in my basement already (yes, that's how bad it is)

OE Audi Parts:

Eccentric bolt M12x1.5x95: 8A0 501 387 C (I measured 94mm length, no big deal)
Keyed eccentric washer: 8A0 501 385 A
Self Locking Nut: N 90635001


BMW Parts:

Eccentric bolt M12X1.5X98: 33321095102
Keyed eccentric washer: 33306786186
Self Locking Collar nut: 33326760668 (Can use the Audi Nut since it's the same size - M12x1.5)

Comparison pics:


Audi washer (35mm dia):


BMW washer (33mm dia):


Audi length (94mm measured):


BMW length (97mm measured):


Note: Thread length is shorter on the BMW bolt (25mm vs ~33mm) however the pics below show that it's not an issue.

Installed:





The diameter of the eccentric is 2mm smaller, so it's not as tight of a fit in the lower control arm, but it will provide that eccentric movement when you rotate the bolt head by putting a bit of pressure against the spindle (inboard or outboard). Recommend inboard pressure on the spindle while torquing the bolt as cornering loads are higher in this direction. Alternatively, if you're a keen welder, you could add a 2mm strip of steel to fill in the gap on your control arm.

While it may be very evident, you need the BMW washer to go with the bolt, as the pattern on the ID is different from the Audi bolt.

Obviously not a smoking gun solution but pretty close.

Hope this helps,

Barry


Disclaimer:
- For those concerned about the bolt shifting due to the 2mm clearance, once torqued to spec I wouldn't anticipate this happening since even the Audi eccentric has a bit of play in the control arm. The clamping force provided should be adequate to react the anticipated in-service loads for a daily driver.
- I have not tested this setup yet so all information presented above is to be used at your discretion. I'm merely sharing info that I've found.

[Silverex]

Pretty sure I got mine off a later model. I’ll post pn later tonight.

[q20v]

Ah no way, so there's already an Audi substitute? Yes, please share!

[q20v]

This one?

https://www.fcpeuro.com/products/aud...bolt-wht000228

Found it on this page:

https://www.audizine.com/forum/showt...-small-fortune

[Silverex]

8A0 501 387 D
Is the one I have. Can’t remember if I got it from ECS or FCP

[q20v]

Cool, thanks for the info. I ended up placing my FCP order last night and bought 2x WHT000228 (from the link above)

So a quick summary

OE Bolt:
8A0 501 387 C
M12x1.5x95

WHT000228
M12x97.5mm

8A0 501 387 D
M12x1.5x86

The WHT000228 seems to be closer in length, I'll report back once it arrives and take the rest of the measurements.

Disregard the BMW option!!

Thanks for the help guys

Barry


** Edit - Correct washer needed as well (WHT000232 - Washer), see posts below for more info. **

[rekrull]

I bought WHT001661 which is M12X1,5X95 and it appears to be a very close match. On the parts diagram it shows as using the same eccentric washer (WHT001656) as the original screw (8A0 501 387 C). I believe 8A0501387D is the one used for the rear toe adjustment and the offset is a bit different. Full disclosure- I haven't installed it. I was able to re-use the old ones last time I had it torn apart.

[Silverex]

Now that you say it I believe you are right the one I have is for rear toe in subframe. The ones for control arms I bet are the ones from FCP link.

[q20v]

Well, overall good to know there are still options out there. I almost bought some NOS from Facebook market place for way more $$ thinking that was the only option.

[PwrWgn]

Looks like the 8A0501387C are still avail from Audi Tradition if you want an exact replacement.

[q20v]

Just to update this thread... the Bolt listed below arrived and it is for all intents and purposes the same size as the old NLA bolt.

Part number:

WHT000228 - Bolt

WHT000232 - Washer



** Updated to include the correct washer 9-Apr-2021 **

[rekrull]

thanks for the update

[SouthAudirowdy]

Are the eccentric washers the same for both the control arm and spindle eccentric bolts?

[q20v]

Let me check!

[q20v]

Just a pile of misinformation in this thread.. what a nightmare!

I just went down a double checked, the washers are different!

I'll correct my posts above so as not to mislead anyone, the indexing notch in the washer is different because the groove in the bolt is in a different position than the B5S4 OEM bolt. (180 degrees off)

So the replacement bolt / washer for the spindle position on the B5S4 is from Audi A3 rear suspension, see ETKA below, part numbers:

WHT000228 - Bolt (#11 below)
WHT000232 - Washer (#9 below)

Sorry to have misled anyone.




Barry

[Gosser]

This q20v guy has no idea what he is doing! BMW parts on an Audi! Might as well order billet bushings from alibaba for the control arms too!

[q20v]

It’s embarrassing, really. I VTB myself, this will be my final post.

[lowestA4]

The genuine Audi rear excentric bolt as well as the genuine excentric washer is still available here in Germany.

I believe I had them listed up in my 2nd restoration parts thread. They shouldn't be super expensive at all.