From digest.v6.n207 Wed Feb 12 14:29:40 1997
From: Pete Read <read_at_arl.bna.boeing.com>
Date: Wed, 12 Feb 1997 08:14:47 -0800
Subject: Re: <E30>'87 325is strut size prob???

Thomas Murphy asks:
>This past weekend I ran into a problem while changing the front
>strut inserts for my '87 325is. The replacement struts came as 51
>millimeter diameter. My strut housing is 45 millimeters, which two
>dealers say is for a 318i (I think '84-'85). The inserts I pulled out
>are Bilsteins with a BMW roundel on them ... was this 45 mil.
>housing and Bilstein insert delivered standard on the '87 325is, or
>do I have strut housings taken from a 318i?

I'd say you have the original front strut (shock). Looking at the latest Bavarian Autosport Catalog 800.535-2002, E30 Bilstein shocks are listed as:

1. E30 Sport Shocks

   (for short spring)

Bilstein# Application

Rear:
B36 2027 3 series '84 thru '91

2. E30 Heavy Duty Shocks

(for normal length spring)

Bilstein# Application

Rear:
B36 2028 3 series '84 thru '91

Bilstein part numbers work like this:

P36: P = Strut insert, 36 = piston diameter in mm. P30: P = Strut insert, 30 = piston diameter in mm. B36: B = Shock, 36 = piston diameter in mm.

The last four numbers (e.g. P30 0334, for '87 E30 front sport strut) give the model applicability and valving.

Notice that in '87, all E30 325 front struts got smaller (30mm versus 36mm shock piston). That 6mm difference is what you found (strut housing dia: 51mm - 45mm = 6mm).

Exchange the Bilstein P36 0335 strut inserts you received for the correct P30 0334 to make life good again.

Hope this helps,

Pete Read
'88 M5