[Saintor]

... à la E46 - every 35000 miles.

Or is it fixed? Just changed them on my 2005. I would have thought that by the end of this series, it would have been corrected, but not.

I will buy probably an E90 and wondered..

[itsbrokeagain]

so far havent seen any issues at all.

[raleedy]

Wait and see.

[Saintor]

If it would be like the E46, we would know then now.

[Herknav]

For us E46 uninitiated, what were the LCA problems?

[CirrusSR22]

The E90 front suspension is a completely different design than the E30/E36/E46. Any issues won't be the same "issues" as older 3 series cars.

[dirty330]

The e46 used a single ball joint strut axle based on the e36.The rear lower control arm bushings are not able to take abuse.The symptoms of them being failed are noises,play in the front end,and shudder during panic stops.
Bmw is using a double pivot spring strut front axle on the e90. It has been used on all 5, 7,and 8 series.It proves to be much more durable.Some other advantages are reduced body roll,reduced front end dive during severe braking,and improved straight line stability at high speeds.Nothing is perfect but its much improved.

[Herknav]

No one made better bushings to fix the E46 issues?

[dirty330]

Absolutely they made improved bushings.There are upgraded 66mm ones available and also I think Delrin made a urethane set too.

[noro]

Originally Posted by Herknav

For us E46 uninitiated, what were the LCA problems?

At 50K miles you were pretty much guaranteed to have control arms bushing gone so soft that every time you tap the brakes a little bit you can feel the feedback in the steering wheel because the geometry was changing. For mechanically inclined this wasn't a problem, the bushing were under $90 for pair and it took ~45 mins to replace.

The advantage of the single balljoint wishbone suspension is less unsprung weight since there is only 1 arm extending to the wheel hub assembly. On the e9X series the suspension uses 2 arms that extend out to the wheel hub assembly. What the new setup loses in terms of more unsprung weight it gains in more durability and also allows for better camber changes when the wheels are turned from side to side.

[Herknav]

Since I havn't been under my car yet, I havn't looked. What sort of material are they using now? There has to be *some* softer material or we would have NVH issues.

[Neurorad]

Originally Posted by CirrusSR22

The E90 front suspension is a completely different design than the E30/E36/E46. Any issues won't be the same "issues" as older 3 series cars.

Control arm noobie here. Rear different too? XI also?

[noro]

Originally Posted by Herknav

Since I havn't been under my car yet, I havn't looked. What sort of material are they using now? There has to be *some* softer material or we would have NVH issues.

The arms themselves seem to be some sort of an aluminum alloy, which has more flex than steel and takes some of the stress out of other parts including bushings, the bushings themselves I don't know, but they appear to have a similar rubbery look.

[F32Fleet]

Originally Posted by dirty330

Absolutely they made improved bushings.There are upgraded 66mm ones available and also I think Delrin made a urethane set too.

+1

[CirrusSR22]

Originally Posted by Neurorad

Control arm noobie here. Rear different too? XI also?

Yep, the E90 rear suspension is totally different than the E36 & E46 which had similar designs to each other.

Your xi does have the all-new suspension design (not E36/E46 based). The xi has a slightly different front suspension than the non-xi cars, but it's still the same general design as the other E90s.

[Neurorad]

Originally Posted by CirrusSR22

Yep, the E90 rear suspension is totally different than the E36 & E46 which had similar designs to each other.

Your xi does have the all-new suspension design (not E36/E46 based). The xi has a slightly different front suspension than the non-xi cars, but it's still the same general design as the other E90s.

Thanks!

[Herknav]

Originally Posted by noro

The arms themselves seem to be some sort of an aluminum alloy, which has more flex than steel and takes some of the stress out of other parts including bushings, the bushings themselves I don't know, but they appear to have a similar rubbery look.

How strong are the stock LCAs? I have read several threads from folks driving the 1/4 mile mentioning wheel hop.

[The Cleaner]

E90 uses support arms like the 5 now, the E30-E46 did not have control arm problems they have bushing that had problems. That design is gone.

Support arm bushings in the E90 "IF" like the X5 and 5ser will fail at 50-70k. It's a very large liquid filled mount that is forward of the control arm. I have 85k on my X5 and I have done them once already.

[noro]

Originally Posted by Herknav

How strong are the stock LCAs? I have read several threads from folks driving the 1/4 mile mentioning wheel hop.

wheel hop has nothing to do with the strength of the control arms, and I think we are talking about front LCAs unless you're talking about xi cars or rear trailing arms, about which I don't know much.

[raleedy]

I have to take issue with the post above suggesting flexibility in aluminum suspension components. Steel flexes. Aluminum (other than gum wrappers) doesn't.

[noro]

Originally Posted by raleedy

I have to take issue with the post above suggesting flexibility in aluminum suspension components. Steel flexes. Aluminum (other than gum wrappers) doesn't.

guess it would just be for weight savings. Does aluminum absorb more energy than steel? perhaps safety is a factor as well.

[runnerx]

Are we suppose to have control arms issues?