Bilstein B4 kit

[SonnyA85]

The ones I removed were originals after 112k! there was no vestige of a label left anywhere on them, sorry.

Yeah mine are coming out at 107k. Some labels on them but nothing to suggest they're M. Would have thought there was a way to tell.
Might need to go to the forum and ask.

go to a dealer and ask for the parts department. say you need to buy shocks. ask for a price on shocks just say you want to shop around don't commit to buying. then ask them to send you the vehicle spec list from factory. give them the VIN and they will send you screenshots by email.

 

[enuff_zed]

Yup, Realoem shows different part numbers for MSport
https://www.realoem.com/bmw/enUS/showparts?id=BT52-EUR-08-2003-E85-BMW-Z4_30i&diagId=31_0646

Wow! Stuck the part number into Autodoc and it comes up with a fancy Bilstein one for £230 !!

 

[enuff_zed]

Fully understand you are wanting to keep it 100% correct, but I can only advise that, as I said previously, I have fitted standard Sachs with no issues at all.
Harking back to my years of modding Capris, it was always understood that up to a 25mm drop on a spring and you could happily keep the standard shock. Any lower and you started to run out of room for manoeuvre.

I would recommend though that you make sure you get the correct, shorter, MSport bump stops.

 

[Rockhopper]

There is nothing to identify the standard shocks as being Msport other than the part number on the label (if its still on there!!). I have B4's on Suplex Msport springs (15mm lower than standard) and it gives a nice comfy ride. I believe though if you want a similar shock to the Msport and cant get Sachs then the B6 i think is a closer match. I prefer the more comfortable ride of the B4's.

 

[Gregory_tolson]

Good luck waiting on those B4's. It took me 2-3 months to get the freaking B6 rear Shock absorbers from Bilstein here in the US. I changed my suspension since both my rear springs were cracked. I got the B6 struts in 2 days, they were manufactured in Cincinnati Ohio. The shock absorbers came in with the boxes super beat up, pretty sure they got boated across the pacific from Asia and it took 7 days for Fedex to drive it across country. But yes, the raw material shortage at Bilstein is very real. They put the shock absorbers literally a week later back on back order. I bought the Lesjofors M-sport springs since i had the original suspension setup on my car. Makes it just a tad lower and rides great and sporty, though the front is sitting just a tad higher which always has me scratching my head. They have substantially settled out over a 1000 miles of driving but still not perfect level.

 

[Dr. Zed]

Yup, Realoem shows different part numbers for MSport
https://www.realoem.com/bmw/enUS/showparts?id=BT52-EUR-08-2003-E85-BMW-Z4_30i&diagId=31_0646

Wow! Stuck the part number into Autodoc and it comes up with a fancy Bilstein one for £230 !!

I'll check the part number on mine. The sticker is sort of still there if I remember correctly.

The odd thing is, when I put my reg into any car parts store it's recommending Sachs and B4's, not the M-sport.

Sounds like the B4 with current spring might be the way to go then. Though looking at the bump stops online and comparing them to mine, they do look totally different suggesting they're M bump stops.

I was thinking of replacing my springs but god knows what I replace them with now. They're still fine, just makes sense to refresh the whole thing in my opinion.

 

[Dr. Zed]

[ref]Gregory_tolson[/ref], Well my contact can get B4's for me by the end of the week. Just the headache of figuring out what the hell is going on with my suspension!

Those B6's do look good though mate

 

[Dr. Zed]

There is nothing to identify the standard shocks as being Msport other than the part number on the label (if its still on there!!). I have B4's on Suplex Msport springs (15mm lower than standard) and it gives a nice comfy ride. I believe though if you want a similar shock to the Msport and cant get Sachs then the B6 i think is a closer match. I prefer the more comfortable ride of the B4's.

I'm liking the idea of the standard shock on M coils to be honest...

 

[Gregory_tolson]

[ref]Gregory_tolson[/ref], Well my contact can get B4's for me by the end of the week. Just the headache of figuring out what the hell is going on with my suspension!

Those B6's do look good though mate

I was nervous they would be too stiff, but my original suspension was so shot (since it was original) that they feel soooo good over bumps. I honestly would hit a pot hole on the original suspension and the car would rattle violently.

 

[enuff_zed]

Could do, but I've not bothered as luckily never had a broken one................. yet!

I swap out the strut, bump stop, top mount and new bottom knuckle bolt.
The rubber spring pads and the drop link I do on condition.
I think you'll find most of the replacement dust covers are plastic. I prefer to clean up the original rubber ones. A liberal amount of Autoglym bumper gel also makes the rubber supple again.

 

[Gregory_tolson]

Definitely replace the springs on the car. Those rear coils are known for cracking where mine cracked in the pictures. Its not worth moving the springs over, plus those Lesjofor springs were veryyyyy inexpensive. I got the M sport ones since i wanted it just a tad lower.

 

[Dr. Zed]

Well this is what's on my shock and matches no part numbers so I have no idea!

I'm replacing top mounts, shocks, knuckle bolt, and plastic cover and bump stop.
Should freshen it up nicely.

 

[Dr. Zed]

[ref]Gregory_tolson[/ref], Well my contact can get B4's for me by the end of the week. Just the headache of figuring out what the hell is going on with my suspension!

Those B6's do look good though mate

I was nervous they would be too stiff, but my original suspension was so shot (since it was original) that they feel soooo good over bumps. I honestly would hit a pot hole on the original suspension and the car would rattle violently.

I always thought my car felt that bad over British roads because it was so low but I'm starting to realise it was likely the shocks being knackered for some time.

 

[enuff_zed]

Definitely replace the springs on the car. Those rear coils are known for cracking where mine cracked in the pictures. Its not worth moving the springs over, plus those Lesjofor springs were veryyyyy inexpensive. I got the M sport ones since i wanted it just a tad lower.z4-1.jpgz4-2.jpg

I would agree about the rears, but never hear much about front spring issues?
The rears are dead easy to change on their own, so if they look ok you could still leave them and see?

 

[enuff_zed]

Well this is what's on my shock and matches no part numbers so I have no idea!

I'm replacing top mounts, shocks, knuckle bolt, and plastic cover and bump stop.
Should freshen it up nicely.

Yes, the 761895 number matches the MSport number on realoem if you check the link I sent.
Also the strut says Sport on the label.
So you do have MSport shocks.

 

[Dr. Zed]

Definitely replace the springs on the car. Those rear coils are known for cracking where mine cracked in the pictures. Its not worth moving the springs over, plus those Lesjofor springs were veryyyyy inexpensive. I got the M sport ones since i wanted it just a tad lower.z4-1.jpgz4-2.jpg

So could I mix the M sport coils with B4's regardless whether my car had m suspension to begin with?

 

[Dr. Zed]

Definitely replace the springs on the car. Those rear coils are known for cracking where mine cracked in the pictures. Its not worth moving the springs over, plus those Lesjofor springs were veryyyyy inexpensive. I got the M sport ones since i wanted it just a tad lower.

My springs aren't gone. The reason i originally removed the suspension was due to the top mount being cracked when I looked under the hood. But since then the shocks are clearly worn out too.

 

[Dr. Zed]

I would agree about the rears, but never hear much about front spring issues?
The rears are dead easy to change on their own, so if they look ok you could still leave them and see?

I'll be honest, I haven't looked at the rears.. Not ordered any parts for them either

As for the parts number. The 'sport' I can see so thanks for that. Missed that, however the part number I can't match. What am I missing? You said the 761895 matched but I don't see that at all mate, sorry!

 

[Gregory_tolson]

yeah, that pic you posted is the M-sport suspension strut. My parts website claims the B6's are an OE replacement solely from a firmness standpoint. They told me B4 struts work with the M-sport coils but you lose that sporty firmness the M-sport struts provided from factory. The part number from factory is that 31316761895 number. The piston housing dimensions on the B6's and B4's is the same.

 

[enuff_zed]

Definitely replace the springs on the car. Those rear coils are known for cracking where mine cracked in the pictures. Its not worth moving the springs over, plus those Lesjofor springs were veryyyyy inexpensive. I got the M sport ones since i wanted it just a tad lower.

My springs aren't gone. The reason i originally removed the suspension was due to the top mount being cracked when I looked under the hood. But since then the shocks are clearly worn out too.

Slowly getting closer
You now know you DO have MSport suspension. so you have the lower springs. If they ain't broke.......................
Can swap rears out later if they do break, but my logic would say with new dampers the spring will be under less stress as it's finally getting a little assistance.
So you either get the expensive B6 option, or consider going standard shock. In that case the B4 looks a little longer than the Sachs?
Add to that my experience with fitting standard Sachs on MSport springs with no detriment.
It's starting to come down to price and availability.