318is, two versions of the rear shock Bilstein HD (b6)?

[onesecond]

I've been looking for a bit and can't seem to find anyone really talking about this. So if you go to most websites, FCP Euro, ECS (and the others they own), Bimmerworld, etc... they have two versions of the the B6 rear shock, part number 24-020282 (universal) and 24-007382 (318is specific on Bilstein's website). This seems to be the only car that has a very specific rear shock and I was wondering if anyone has any info on that shock and how it differs from 24-020282

Just to further emphasize how odd this is, this only happens on the B6 lineup rear shock and no where else. In the B4 and B8 all part numbers match for both front and rear to all other models and the B6 fronts are the same across all models as well (strut size dependent)

Edit: Is this possibly due to the small case differential?

[roguetoaster]

There is no way the weight difference of the differentials is substantial enough to warrant a different shock when fronts are shared between 6 and 4 cylinder models.

Bilstein says that 007382 pairs with early model front of 45mm diameter and the other one is for late models. Search for the Bilstein range catalogue if you want to see for yourself.

[onesecond]

Where/how did you find that so quickly? As for whenever I go to search for which shocks to use on a 318is on Bilstein's website it always lists the part number 007382 and never 020282

[ForcedFirebird]

The 318's didn't get trunk tar and a smaller diff. Overall they are a fair bit lighter than a 6cyl car - not surprised there's a different part number.

The b6 (aka HD) are the stock replacements for "S" models. My first e30 had the original shocks/inserts, they were inverted, yellow, and were the same length as HD's but instead of having a Bilstein sticker, a roundel was engraved in that spot.

B8's are meant to be used with shorter/stiffer springs (sport). b4 are economy/touring (aka mushy).

[roguetoaster]

Where/how did you find that so quickly? As for whenever I go to search for which shocks to use on a 318is on Bilstein's website it always lists the part number 007382 and never 020282

When you want real info just go right for the catalogue or tech sheets. While I agree with FF that M42 cars should be lighter in the rear it doesn't account for the shock specification when one considers ROW models, and it tracks, to me at least, that the 45 and 55mm front inserts have different damping characteristics, necessitating a different rear setup to control body motion.

[ForcedFirebird]

Yeah, wondered if it was for early 318 (non-iS, m10/40 cars), didn't even go to a catalog, just bought so many sets of shock for the shop over the years.

They early cars also had the battery in the front tray, along with the 45mm dampers, no sound deadening, no ABS, etc. Lightest of all the e30's, by like 500lb

[onesecond]

When you want real info just go right for the catalogue or tech sheets. While I agree with FF that M42 cars should be lighter in the rear it doesn't account for the shock specification when one considers ROW models, and it tracks, to me at least, that the 45 and 55mm front inserts have different damping characteristics, necessitating a different rear setup to control body motion.

Not that I don't believe you but if I go to the Bilstein website and search by part number the result gives me this https://cart.bilsteinus.com/details?...66840683671351 which only lists it being compatible with a 1991 318is and no info on the 45mm strut housing (unless I am blind which is not uncommon for me)

[roguetoaster]

I was just being lazy and not linking their PDF catalogue, which I will continue to do, although it's not hard to find. Clearly either one will physically fit any E30, but heaven only knows the actual difference in specs.

Basically, buy whichever one, and you probably would never notice the difference if someone swapped in the others in the middle of the night.

[onesecond]

For anyone else who may come across this, seems like yeah it doesn't really matter which one you get and the 007382 was designed for both 45mm and 51mm struts. Either will work with either front strut design ie your front strut size doesn't matter at all.

Here's a link to an older catalogue: https://www.bilstein.com/fileadmin/u...015_GB_low.pdf