Damper failure: what to do?

having only completed some 200 miles since refurbishing the front suspension, i have just now discovered a sigificant oil leak from the top of the front left damper. (A leak large enough to leave a visible, dinner-plate sized oily patch on the drive after one night)

My options are:
1.) Do nothing until it fails completely.
2.) Replace both dampers (complete struts) with original BMW OEM.
3.) Re-fit existing struts with Bilstein inserts.


I'm really not looking forward to doing all the work again , but I've read the various postings on this forum about the dampers and I tend to favour option-3.

However, I think I need some help:

What is the correct model number of the Bilstein damper inserts and where's the best place to get hold of them? Will they be harder or softer than the original M-sport dampers?

Also, should I keep the original M-sport springs, which had a little rust, but were stripped and repainted with several coats of polyurethane, or should I fit Eibach springs?

For the eibach springs, is it necessary to fit them front and rear? (At some point I will probably change the rear dampers to also to Bilsteins.)

Any advice appreciated.

Thanks for the advice. I just checked with my local dealer and the BMW damper struts are each GBP 825.97 (incl 20% VAT) , but new wheel hubs need to be bought to go with them at GBP 161.36 each. Probably they woulkd give me 10 - 15% off the list price before tax. Still, that over GBP 1500, so I think the Bilsteins are definately the more cost effective option here.


Reinhard, I guess the picture shown in your link is just a generic pic? I assume that what you get is the insert kit for the existing struts?

.. a bit more ?

I found that in the UK, pretty much the lowest price is GBP 208 each (incl VAT) from 3 or 4 different retailers.

Reinhard's website link in Germany has the pair for Euro 398.- incl. delivery to UK (about GBP 330), but I can't work out how to add the delivery to the "checkout" price, as it only gives the option "collect at shop" and I'm having trouble explaining this to them.

I had a look at the Eibach springs, but from what I've read the front ones are considerably stiffer than the CSi springs, and I think that would be too hard, so I'll keep the existing M-sport ones.

I've kind of resigned myself to (re-)doing the job, but the springs are an absolute pain to put back on, as the screw-type spring compressors that I have, can only attach on the middle turns of the spring and even when these are fully compressed, it's still not short enough to fit the lock-nut.

Hopefully, the Bilsteins may be marginally longer ?

Have done. Thanks!

OK, the new Bilstein dampers have just arrived.

When fitting these new inserts into the strut, is it a good idea to refill the strut with a small amount of oil? (engine oil?)

Some say that the oil will help heat disipation to keep the inserts cooler. However, others say that the oil could promote some fasteners on the bottom of the insert to come loose.

Any suggestions?

Thanks.

Zitat von MB;94003

Arnie, I did the same job a while back, B6's, camber plates and new M sport springs, ending up with the front of the car 30mm higher than before. Hopefully you will not find this, I still have no idea of the cause.

One thing about the Bilsteins is that they use gas pressure, which has a side-effect of trying to keep them extended with a force of about 50kg each, effectively helping the springs. The Boge OEM ones don't use gas pressure and the piston rod will stay put in whatever position. This effect of the gas pressure was (is) a concern, since the last time I used Bilsteins - on a jeep - the rear, which was quite light, increased by about 15 cm in height! Not a problem for a jeep, of course (particularly at the rear), but for the front end of a car ?

However, I am keeping the original M-sport springs, which will have probably sagged a litle, compared to new and eventually, I will need to fit new rear springs, so I am hoping that overall, the result will look OK.