OEM springs

A

A-minor

Member
 Hants
Following on from my earlier thread about my Z4's suspension, I have been trying to figure out the OEM spring part numbers. RealOEM doesn't give this info, but I have found out elsewhere on the web that the part number for the 30i non-adaptive / non-Msport rear spring is 33536785084.

Now BMW want well over £100 each for these, and I can't find out who makes them so difficult to buy elsewhere and still be certian I am getting OEM spec. There are websites offering equivalent springs from other manufacturers but I'm not sure whether they truly are OEM spec, or are stiffer/lower (which I don't want). Has anyone been through this process and know where you can get OEM spec springs without having to pay dealer prices?
 
I have just recently replaced the rears in our 23i.
After going through the same as yourself, there is very little info out there, even a definite answer of who makes the original springs.
When I asked BMW if they were Sachs they guy said they might be but not definite.
Sachs seemed to be out of stock everywhere I looked so ended up getting Suplex. Although BMW said they could get them in 2 days.
These are Msport springs and fit and feel just like the originals.
Got them from here although this company seems to have lots of different names and comes under Autodoc.
Took just over a week to arrive from Germany.
https://www.buycarparts.co.uk/bmw/z4-e89/31016/10213/coil-springs?criteria%5B100%5D=HA&sort_supplier%5B%5D=10708
 
Hi.

I think I have two rear springs in the garage. Car had done 33k before I put Eibachs on. It's a 30i M Sport non adaptive. Let me know you're interested and I'm sure we can work something out. :D

Graeme
 
Thanks Graeme,
They don't happen to have a part number marked on them do they? My car is an early E89 before the Msport option was available, so I assume the correct factory spec would be non-Msport springs.

Edit: I found a Suplex catalogue online which lists spring types for 'vehicles with standard suspension' and different spring types for 'vehicles with M-Sports or Adaptive M-Sports Suspension'. It says the rear springs on a 30i manual with standard suspension should be marked as 'S1'.
 
That fits in with the info on the Suplex catalogue. Here's the relevant page in case anyone finds it useful...
 

Attachments

  • Suplex-E89.jpg
    Suplex-E89.jpg
    225.5 KB · Views: 684
The spring chart makes interesting reading when looking at the 20i vs 28i in manual and auto mode..

In standard suspension the 20i and 28i have same rear springs with front springs being the same between models but varied for auto vs manual

In sport suspension the 20i and 28i have different rear springs with front springs on 20i same for auto and manual but 28i have a different spring for auto only

I wonder if they randomly alter them, track test them to select the best or do some other weird calculation..

The weight logic does not hold up as for example the 18i 29i 30i 35i all have the same m sport rear spring but the 28i is different..

Weird...
 
You must log in or register to reply here.
Back
Top Bottom