e34 standard vs M5 upgrade suspension

[Vanguard]

Well my 530i is starting to develop the 40-60 mph shimmy on braking (usually when going downhill). Since my research here and on bimmerforums.com seems to indicate that thrust arms at a minimum need to be replaced, I've been doing a lot of shopping both on eBay, local vendors and at the major websites - bmaparts, autohausaz, pelican parts, bavauto etc.

Some vendors offer an M5 upgrade, so I'm wondering what the differences between the stock 530i suspension and the M5 suspension might be. I haven't been able to find many differences other than aluminum vs steel.

[BillionPa]

first things first, make sure that the parts in that "M5 upgrade" kit are genuine Lemforder products and not Meyle, Karlyn, or the dreaded Hamburg Technik.

second, M5 upper control arm bushings are heavy duty bushings and last longer, the lower control arms are aluminum (the 530 should also have aluminum lower arms)

the "kit" on pelican parts is the cheap parts available, dont get it. pick and choose the lemforder parts. on bavauto, the parts are of unknown vendor, and most are cheaper than the cheapest lemforder parts.

in addition to just the parts themselves, get new bolts and self locking nuts for everything you take apart. also since the shimmy is only during braking it could be your brake rotors warped.

[Brandon J]

You are doing the right thing in researching to replace the front suspension components not just one part (pair). FYI: Below is a list of thrust [arm] bushings from hard to soft:

1. Urethane - squeal if not regularly lubed and ride hard
2. e34 M5 - harder durometer rubber than stock and solid
3. e32 750 - harder than stock, but still has gaps in rubber for ride comfort
4. Stock - with any suspension or brake upgrade will NOT last long

other notables:
1. e31 - have bearings so no need for pre-load, are expensive, may last long in an e34
2. Aluminum - does make a difference when tuning a suspension, not as tough as steel, so do not get if only a daily driver, but good is using sport suspension

Still use the Lemforder products. Also, BMA does do their research. They have found some other brands out there that are cheaper, but are retagged quality parts.

Do buy a some good ball joint separater tools or properly sized pickle forks (that sit on the actual ball) with a small sledge.

[BigKriss]

Not trying to sound like a dick Brandon, but the e31 control arms are only for the lower control arms and all are aluminum.

other notables:
1. e31 - have bearings so no need for pre-load, are expensive, may last long in an e34
2. Aluminum - does make a difference when tuning a suspension, not as tough as steel, so do not get if only a daily driver, but good is using sport suspension

Still use the Lemforder products. Also, BMA does do their research. They have found some other brands out there that are cheaper, but are retagged quality parts.

Do buy a some good ball joint separater tools or properly sized pickle forks (that sit on the actual ball) with a small sledge.

[Brandon J]

Not trying to sound like a dick Brandon, but the e31 control arms are only for the lower control arms and all are aluminum.

Aww ooops, yup, but are notable when applying to changing all the front control arms in this. Yup, all aluminum so no steel option, as in the e34. I should have been clearer about how I wrote this, thanks. Sounds like you were adding and not correcting. Well, hope all can/will use the info in their decision making.

[genphreak]

Aww ooops, yup, but are notable when applying to changing all the front control arms in this. Yup, all aluminum so no steel option, as in the e34. I should have been clearer about how I wrote this, thanks. Sounds like you were adding and not correcting. Well, hope all can/will use the info in their decision making.

As much as I hat cheap arms, my experience with the $115/pr aluminium Lower Control Arms from FCP Groton so far is great. I would however never by a non-Lemforder thrust arm or not get a non-750/M5 or urethane bushing... Nick