underbuilt BMW e34?

[ericbendler]

Ok....Here are the facts. I have replaced pretty much every part in my suspension sans the rear shocks (which are next).

I have always had a problem with the shimmy, and my new brembo CD&Slotted rotors seem to have warped within 5,000 miles.

My question, is that I have read that the suspension was intentionally built light to be more responsive. Does "built light" mean under-built?

I have 18" rims with 235/40/18 tires. I expect some tire wear, squirliness by the steering on uneven pavement, and a rough ride.....

BUT I DON'T expect my repair man to tell me that I have to take my kick-ass wheels off to get the shimmy & toe problems out!

I guess what I am asking for is a no-BS assesment of the undercaraige of the e34. Will I ever get ride of the shimmy, and what's up with these rotors? Has this happened to anyone else?

By the way. I love my e34.

[Alexlind123]

I havent really looked at the suspension very closely, but i think they may have sacrificed some long term durability for pure performance. Generally BMW doesnt do this though (look at the m30 engine, for example).

[diamond777]

i think you are asking alot for a car engineered to ride on 16 inch wheels to perform perfect with 18 inch wheels nice wheels btw

[Zeuk in Oz]

I run 60 series tyres on stock 15 inch bottlecaps and the ride and handling is perfect.

Stock rules ! :)

[Paul in NZ]

the wheels themselves may be contributing.Are they straight,round and of the correct fitment ie offset and hub bore...my tyre man told me to expect to bend wheels and to do more than normal maintenance on the suspension if i run my 17 inch wheels..If you run plus two there will be issues you are running plus three....

[wingman]

Yep! 65 profiles on bottle caps. Smoothe as silk and not an ounce of shimmy.

[pundit]

I don't think you can blame the E34's suspension as such.

If yours is lowered (which it looks like) then that will increase the negative camber in the rear & accelerate tyre wear on the outside. Big wheels with low profile tyres will suffer even worse wear from any misalignment & won't absorb the rough stuff as well as cushy 15's. Assuming nothing is bent or out of round then camber adjusters will help solve tyre wear problems.

Bigger wheels and lowering springs will create other problems that aren't necessarily the fault of the E34's suspension design which I wouldn't describe as 'underbuilt'.
Since I fitted 17" 'T' Stars to mine I'm definately more in touch with every bump, shimmy & rattle... not as forgiving as them old 15" basketweaves and the rest of my suspension is standard.

I'm considering fitting some Eibach Prokit springs to mine but not until I investigate camber adjusters and whether or not I can get out of my drive without scraping the underneath. I intend getting 40,000kms out of a set of tyres (with sensible driving) so lowering springs without camber correction is just a stupid concept unless you dig buying two sets of tyres every twelve months.

A solid (non indepedent) rear axle will prevent camber induced tyre wear but hey... they're definately 'underbuilt'! ;)

I didn't vote because I think it's basically a dumb poll. :)

[Russell]

IMO,this is asking for trouble all around. Front and rear suspension geometry changed due to lowering, harder riding tires etc. Why not replace all the bushings with hard plastic and metal while you are at it. :)

Seriously, Have you replaced any/all of the steering components including idler arm components. Also, there may be some rear steering due to worn bushings or dog bones in the rear suspension. Not sure you have done anything there.

Yes, IMO, the suspension require more and expensive upkeep than a typical car. That I do not like.


Ok....Here are the facts. I have replaced pretty much every part in my suspension sans the rear shocks (which are next).

I have always had a problem with the shimmy, and my new brembo CD&Slotted rotors seem to have warped within 5,000 miles.

My question, is that I have read that the suspension was intentionally built light to be more responsive. Does "built light" mean under-built?

I have 18" rims with 235/40/18 tires. I expect some tire wear, squirliness by the steering on uneven pavement, and a rough ride.....

BUT I DON'T expect my repair man to tell me that I have to take my kick-ass wheels off to get the shimmy & toe problems out!

I guess what I am asking for is a no-BS assesment of the undercaraige of the e34. Will I ever get ride of the shimmy, and what's up with these rotors? Has this happened to anyone else?

By the way. I love my e34.

[ericbendler]

Ok, A couple of answers.

Dogbones, thrust arms, control arms, tie rods, & rotors replaced.

I don't mean to push that it is underbuilt for 18's. I have heard from my mechanic and a couple of articles that it is on the verge of underbuilt due to it's performance characteristics.

[Tom Bombadil]

Dogbones, thrust arms, control arms, tie rods, & rotors replaced.
I am replacing much of that on my recently aquired 525iT, if only because of the age of the original components (car has 85k).

It is rock solid, with no shimmy or vibration. Even with its new M5 wheels and 235/45/17" tires.