[rv7charlie]

Hi,
A quick search for options yielded more info than I could readily absorb.

I just discovered a leaky rear shock on my 2008 328i, and need to order a pair of replacements. Any thoughts on a reasonably priced make/model, for a daily driver? No desire to mod or increase performance; just restore normal handling. Obviously want to avoid going *too* cheap and hurting the car's comfort/performance.

Thanks,
Charlie

[Fireball5657]

Originally Posted by rv7charlie

Hi,
A quick search for options yielded more info than I could readily absorb.

I just discovered a leaky rear shock on my 2008 328i, and need to order a pair of replacements. Any thoughts on a reasonably priced make/model, for a daily driver? No desire to mod or increase performance; just restore normal handling. Obviously want to avoid going *too* cheap and hurting the car's comfort/performance.

Thanks,
Charlie

I have a 2011 328i, and I did a shock and strut replacement with Bilstein B4's. Car handles much tighter around corners, it's much more controllable on the highway, but it's not stiff like B6's or B8's.

Do note that there will be two different sku's of the B4's. One for sport suspension and one for standard suspension. The shocks/struts for the sport suspension will have less travel since sport springs ride lower.

Bilstein is a reputable name brand for shocks and struts, and the B4 line is their OEM+ replacements. They're ever so slightly stiffer than stock, but aren't a really huge performance upgrade. I highly recommend them if you're not going for a upgrade over what the car came with.

[lowrydr310]

Sachs made the OEM dampers and are available for about $20 less than the Bilstein B4. I know the claim is that Bilstein is slightly stiffer than OEM but I couldn't tell any difference. I have one E90 with Sachs rear shocks and a E93 with Bilstein B4 rear shocks and honestly the Sachs feel firmer. But who knows, they're so similar it doesn't really matter.

Also, it's the same deal with Sachs, there are different part numbers for sport vs non-sport suspension.

[rv7charlie]

Thanks, guys. I just ordered the Bilsteins; probably would have saved the money if I'd thought to refresh this page before ordering. (I'm cheap.) On the other hand, maybe the Bilstein lifetime warranty will mean that they outlast me.

Hope there's no issue with installing them in the rear without doing the front struts. Probably need those by now, but honestly, without a trusted BMW mechanic on tap, I'm leery about messing with wheel alignment that isn't broken.

[ppointer]

I have two e92's. Both have about 20k miles on them. One has new B4's, and the other has the stock Sachs. The B4's ride and handle better than the Sachs, all subjectively measured through my butt. If you need science, I'm not helpful there. I vote with my wallet, and I'll probably get some B4's for the other e92 later in the fall.

[rv7charlie]

I'm baaaack...
Pulled the left side trunk liner, installed the shock (non-event), and then got to the hard part: re-installing the liner. The front edge of the liner actually wraps around the seat back liner, and with the stiffener channel about 2" from the seat back, there's no way I've found to get the flange of the side liner back past the seat back liner unless I butcher the molded side panel at the top.

Any tips/tricks? Remove the back seat back? (Ugh)

[rv7charlie]

Followup to the previous post. Finally discovered that if I unlatched the top of the seatback (non-folding rear seat), I could force the seatback forward just enough to get the side panels back in.

Final data point for future newbies: The shocks do *not* come with the rubber damper mechanisms, and the top ones may well be in less than ideal condition. They also don't come with the dust shrouds, and the rubber in the top of the dust shrouds may well not be in great shape, either.

I'm sure it's my fault for not knowing this, since the last time I bought shocks was back when mfgrs seemed to care about including the parts that logically could be considered part of the item you're purchasing....

Thanks for the recommendations on brand/model; the car really does ride much better now.

[bmw_solid]

For the life of me, I don't get why nobody talks about the bumps stops?

What are you guys installing?

Using original bump stops? (pathetic decision IMO)

Or:

Brand New bump stops? If yes, what make are you going for? Bilstein or SACHS OEM? Or BMW Genuine?

Surely bump stops will affect ride and handling and different makes will matter too?

I recently fitted rear B4 Sports to my car with genuine BMW rear bump stops but the ride was too bouncy and not comfortable at all. Then I ordered Bilstein bump stops (m-sport ones) and the ride got better. The BMW ones were quite soft compared to the Bilstein ones. Could it be that the softer the bump stop, the more bouncy the ride gets? Stock tyre pressures

[lowrydr310]

Originally Posted by bmw_solid

For the life of me, I don't get why nobody talks about the bumps stops?

What are you guys installing?

Using original bump stops? (pathetic decision IMO)

Or:

Brand New bump stops? If yes, what make are you going for? Bilstein or SACHS OEM? Or BMW Genuine?

Surely bump stops will affect ride and handling and different makes will matter too?

I recently fitted rear B4 Sports to my car with genuine BMW rear bump stops but the ride was too bouncy and not comfortable at all. Then I ordered Bilstein bump stops (m-sport ones) and the ride got better. The BMW ones were quite soft compared to the Bilstein ones. Could it be that the softer the bump stop, the more bouncy the ride gets? Stock tyre pressures

Where did you find Sachs and Bilstein branded bump stops?

When I refreshed my suspension, the only options for bump stops were BMW, Rein, or Febi-Bilstein. I've seen and used all three on the various E9x cars I've owned and they all seem identical, only difference being the Febi-Bilstein ones where a white foam while the Rein and BMW ones were an identical yellowish color. They all felt the same.

[bmw_solid]

Sachs and Bilstein are both available on Autodoc.com

You can go to sachs parts finder or Bilstein parts finder to find out your part number.

That's interesting what you say about the Bmw, Rein and Febi. So it means the bump stop doesn't make much of a difference no matter what the make...quite contradicting to the science unless all makes are there or abouts equal to BMW Spec...material, shape etc...

The Bilstein ones are significantly harder than the BMW ones. The bmw squeeze about the first section then it stops squeezing....the Bilstein ones hardly squeeze at all...but this is a hand experiment...surely with the weight of the car acting on it, they would both squeeze around the same?? I don't know.

It's weird because my car, 320d LCI M Sport...some days it feels very comfortable, slow rebound rate, progressive bump absorption but some days it feels opposite...fast rebound rate, not really progressive bump absorption, firm and jolty. 116k miles and no drastic change in weather at all... I'm attributing it to shot front suspension, which I'll be replacing the whole strut assembly with B4 sports, Sachs springs and Lemforder mounts.

[lowrydr310]

I actually created a separate thread before I refreshed my suspension, specifically asking if there were any differences in bump stops and the consensus was no.

I read a ton of posts saying BMW refers to them as auxiliary springs and that they're engaged when the car is sitting, etc. but I checked my fresh B4 struts and shocks with all new hardware and when the car is sitting on the ground there's a good 2.5" of travel before the bottom of the bump stop engages the top of the strut tube.

[bmw_solid]

Can i have a link to that thread Please? I'd be interested for sure.

Yes, these cars don't ride on bump stops....I'm 90% sure

But the B4 are nice shocks and give OEM feel....I wouldn't go B6 B8 or Konis or lowering springs or M3 arms and bushes unless im tracking it.

[vester86]

RealOEM:

front bump stop is 31336767333 "additional shock abosrber, front" but that is just the bump stop only (for sport suspension; w/o sport suspension is 31336771352)

boot is 31331094749 "protection tube"

Part no. 31302405872 on realOEM appears to be "Repair kit, additional damper guard tube" appears to be bump stop and boot, for whatever reason description is misleading, says rear but appears to be front. 31302405874 is the same part for standard suspension.

for the rear, the sport suspension bump stop that appears to come with the tube ("auxiliary shock absorber, rear") is 33536767335, standard suspension is 33536767334

[whyzee125]

Originally Posted by lowrydr310

Sachs made the OEM dampers and are available for about $20 less than the Bilstein B4. I know the claim is that Bilstein is slightly stiffer than OEM but I couldn't tell any difference. I have one E90 with Sachs rear shocks and a E93 with Bilstein B4 rear shocks and honestly the Sachs feel firmer. But who knows, they're so similar it doesn't really matter.

Also, it's the same deal with Sachs, there are different part numbers for sport vs non-sport suspension.

People love claiming that the Bilstein B4s are 10% stiffer so they can brag about having an upgrade but the B4 is literally a stock replacement, nothing more, nothing less. I think your butt dyno is calibrated well.

to the OP, B4 or sachs or Koni orange are all good OE replacements and will all perform like your factory shocks did when the car was new.

[pbedrosi]

Can you swap only the damper for sports suspension on a car without sport suspension? shorter travel but someone (maybe on this form) mentioned they liked it over large bumps.

[whyzee125]

Originally Posted by pbedrosi

Can you swap only the damper for sports suspension on a car without sport suspension? shorter travel but someone (maybe on this form) mentioned they liked it over large bumps.

The shorter travel would be from slightly lower springs. Shock valving will be very slightly different but I'm almost positive you wouldn't notice the difference if both were new.