Why does the dust cap make so much of a difference?

[BennyM]

I've been researching new bilstein HDs to replace my blown front shocks. And while I don't mean to beat a dead horse by brining up the dust cap nut-size debate all over again, I really don't understand why the dust cap makes such a difference. Obviously a 19mm nut won't fit on a 22mm shaft, but if my car has a 22mm nut and a 1.25" dust cap, what's stopping me from using a 2.5" dustcap? The nut should still go on OK, right? It's 22mm regardless.

I ask because no matter where I look, the 1.25" dust cap version costs $20 more than the 2.5" dust cap versions. Seems silly to me that I have to shell out an extra $40 because of that. Can anyone make sense of this for us?

BTW, Tire Rack is selling the Bilstein sports for $130 a piece right now...cheaper than some of the HDs. If only I had lowering springs....

BennyM

[632 Regal]

the shaft that goes through the bearing is a different diameter. Some struts have the smaller shaft but come with a sleeve spacer so they will work in both applications.

[repenttokyo]

the sports are a better choice than the hd's, lowering springs or not.

[BennyM]

the sports are a better choice than the hd's, lowering springs or not.

Why do you say the Sports are better than the HDs? I've heard they were too stiff.....especially if you live in pothole-country like I do. I was also under the impression that the sports only worked properly with a lowered car....that's why I mentioned the lowering springs.

[632 Regal]

I have an opinion of the bilsteins, rather negative to say the least. I found the sachs/boge to be firmer when needed and more complacent on regular travels. my thread was wiped out so i can only offer this.

http://www.bimmernut.com/forum/showthread.php?t=12167&highlight=bilstein




Why do you say the Sports are better than the HDs? I've heard they were too stiff.....especially if you live in pothole-country like I do. I was also under the impression that the sports only worked properly with a lowered car....that's why I mentioned the lowering springs.

[BMWCCA1]

In most Bilstein BMW applications in the last twenty-five-years the Sports are valved exactly the same as the HD. The only change is the length. The Sports are designed to work only with lowered springs. The HDs with stock ride-height.

[genphreak]

I've used them on e28s and e34s. I mostly agree with Jeff's opinion of them, although I've never seen a Billie fail myself (and found them to last far longer than I wanted them to as you get sick of the ride pretty quick in a street car). Both HDs & sports are hard as nails, and are re-valveable and re-buildable which is great (though I'd rather replace them on a street car).

I know shocks fail if there is not enough oil in the tstrut housing to keep them cool, but doubt this is the reason for the numerous Billie failures one can read about online.

To be honest, I actually felt the Sports with M-tech springs gave a more comfortable ride than HDs with stock springs on the e34... but its hard to pick the difference hardness-wise.

Both are apalling in comparison to the Sashs/Boges (though Turbo Boges are hard to come by) and the Konis.

IMHO, form worst to best it goes;

For 'spirited driving' with lowered springs
4. Bilstein- 3. Most others- 2. Boge Turbos 1. Koni sports

For cruising with stock springs
3. Bilstein standard (aka 'Touring') and probably 2. all budget choices, 1. Boge Automatics (maybe stock Konis are the same/as good (I've never used them)?)

For racing;
Billie sports or Koni Sports, Billies would be acceptable as you aren't interested in comfort on the track (Contrary to my general dislike for them, they do well perform when racing).

Most E34s should have the 3mm spring pad installed when doing the front to reduce front ride height by 6mm, as the rear springs tend to sag over the years (the result being that the car rides higher at the front and lower at the rear).

Any change should generally include the rear (upper) shock mounts as these are pretty notorious for failures.

[BennyM]

Well thanks a lot guys! You've now made my purchase far more confusing. I've read a lot of posts on this and had always thought that the billie HDs were The **** in terms of ride vs. comfort and that they lasted forever. Now you're all telling me they're just ****. Sheesh. Seriously, thank you for the input. I'm definitely reconsidering. Genphreak, I just want to clarify: So, you're saying that the Bilsteins are worse than most other brands for both sport and touring suspensions? Is the only worse option KYB? I was going to go for the Billie Tourings, but I read that they failed far more frequently than the monotube design. I just want something just slightly firmer than stock.

Thanks.
BennyM

[repenttokyo]

i don't understand why people are so down on bilsteins in terms of ride quality. mine ride very comfortably, and Quebec has some of the worst winter-destroyed roads on the continent. i've never heard anyone say bad things about bilsteins aside from these posts here.

[BennyM]

i don't understand why people are so down on bilsteins in terms of ride quality. mine ride very comfortably, and Quebec has some of the worst winter-destroyed roads on the continent. i've never heard anyone say bad things about bilsteins aside from these posts here.

Repent, do you have the HDs or the Sports?

[632 Regal]

consider the sachs/boge "Turbo" they used to call them, going on 3 years and I only blew 1. The ride is much better and it's almost impossible to bottom them out. The handling feels tighter than the billies too.

[repenttokyo]

Repent, do you have the HDs or the Sports?

i'm on the sports, with eibach lowering springs. i autocrossed the car pretty hardcore, and it performed well there and still provides me with great comfort on the street. i have bilsteins in my miata as well, and that car rides much rougher than the BMW - obviously, but still, the difference is notable.

[Tiger]

I have Bilstein Sport for over 8 years. Zero problem with them. At first when installed, may seems a bit stiff. but as mileage pass by, it softens up and is now very comfortable.

In beginning when I first installed it, it seems rough especially when I hit a good size pothole or bump and I was confused. As a couple years passed by, I realized it was because of my sway bar links that was shot. Once I changed the sway bar links, everything was super smooth and perfect in every way.

The moral of this story is don't forget your sway bar links... it is very crucial to the whole suspension and if this is not fixed, it is very possible to have blown shocks much faster than it should regardless of brand. Sway bar does have big job too in addition to protecting shock absorbers from excessive movement on hard impact.