740iL steering judder

I've just phoned my local BMW Main Dealer and they say (predictably) that it could be almost anything.

I then phoned my local independent BMW garage and he says without hesitation it's warped brake discs.

That's predictable too but as likely as not to be wrong.

They're right to say so.

Find another garage. You can't diagnose this sort of thing accurately over the phone anymore than on a newsgroup.

In terms of the most *likely* reason I'd plump for steering/suspension wear before all others.

It's not that cut and dry. I've seen that both be true and not true.

The BMW I have doesn't have these parts but an S clas Merced3s I have has a very equivalent part. Whaty happens is when the front wheel asembly is perfectly ba;lanced and round the problem does not manifest itself, but when a tire ir off (in my case separated treads) or an out of round rotos then an otherwise nonb-noticable problem exacibated by the brake rods causes the car to feel like it's tearing itself apart.

So, I woul dbet money on the fact your rotor is out of round or tire is uh, suboptimal and that fixing those would alleviate but not cure the problem. The brake rods are what's wiggling and almsot certainly need to be repaired.

I jsut went through this too.

Which is easy to verify with a dial gauge - measure radial runout before you throw more money at somebody's wild guesses.

Wise words, Richard.

I've just looked up the meaning of 'radial runout' and apparently it means the extent to which the disc's radius varies or (in my own words) the extent to which the disc is not a true circle.

Well, the car's going in to the independent BMW dealer on MOnday morning.

I'll keep everyone informed of developments.

Oh. I thought it was side to side wobble. I had a car once that had the same symptoms and was told they put a dial gauge on it to measure radial runout, found it was really bad, told me they were warped, put on new rotors and fixed it when 3 other shops just charged me a forture for things that didn't fix it.

We always assume new parts are flawless. This is not always true and sometimes they don't stay new long. Good luck.

I had same problem replaced front brake discs myself

VERY easy

cost $70 for both !

no more judder

Well, the Independent BMW guy road tested the car said the judder doesn't feel like the usual judder caused by warped brake discs.

He took the wheels off and reported that both discs are rusted on the insides and the edges, the offside lower control arm and bush are worn out and the nearside control arm isn't great either.

It'll be ready tomorrow about lunchtime.

Well, the Independent BMW guy road tested the car said the judder doesn't feel like the usual judder caused by warped brake discs.

He took the wheels off and reported that both discs are rusted on the insides and the edges, the offside lower control arm and bush are worn out and the nearside control arm isn't great either.

It'll be ready tomorrow about lunchtime.