Very shaky steering

[uggers2k]

Hi all,

Was driving my Z3 earlier and was doing about 70mph when the steering wheel started shaking really violently, so much so it became uncontrollable. Thinking I had a puncture, I pulled over and the tyres were fine. Jumped back in the car, carried on driving at it has been fine since. (No shaky steering)

Now researching the problem, It seems as though a sticky brake caliper is to blame. Are these an easy ifix for a DIY'er or a garage jobbie?

Many thanks

[Mike Fishwick]

A siezed caliper is doubtful - always try everything before buyiung new bits in the hope that it will cure the problem.

I have just replaced a very sticky caliper, which would not move in under all the pressure I could muster with a screw tool, or out with 8 bars of compressed air behind it - but it did not affect the steering at all.

I would go back to the same piece of road and try to recreate the problem. If the fault recurs, walk back to the spot and have a good look at the surface.

Your problem sounds like severe tramlining, and if so there are lots of possible causes.

[Deano1712]

You are mostly likely going to need a new caliper. The piston will be rusty and you have to buy the complete caliper. ebay shows them at £70 to £100 each. Its a common problem with 10+ yr old calipers.

[Mike Fishwick]

Ebay at £70 to £100 each? You should try thinking about other sources. As I have been previously scolded for remarking, Ebay can be a nest of thieves!

I have just bought a pair of calipers for my 2.8, reconditioned by Borg & Beck (reground cylinder with slightly oversize piston, and replated) for £112 a pair, with the £44 surcharge returned on the pair of old calipers. The source was German Swedish and French . . . think locally before Ebay, every time.

But - for a sticky caliper to cause these symptoms it would have to keep applying the brake, making the car pull to one side, which does not appear to fit the symptoms - or does it? And if so, why did it only happen for a very short time?

Think hard before spending your money, and don't be disappointed if it does not cure the problem.

[alan36]

I had this with my E36 3 series. It was actually the bottom wishbone that was at fault.

Its worthwhile jacking each front wheel up and get someone to move the wheel while you look at the balljoints and the rear bush.

[BladeRunner919]

I'm with Mike - I just don't see this being brakes. It's much more likely to be a 'weakness' in the suspension or steering (I'd start with Alan's suggestion of the rear bush on the wishbone) that was exposed by the exact set of circumstances at that point in time.
I have a Range Rover that at just the right speed and hitting just the right size bump/pothole, will violently shake it's front wheels. It's down to a slight looseness in the suspension that I haven't got around to fixing.

[z3bedee]

If you think that you have a sticking caliper simply jack your car up and see if the wheel spins freely by hand. I have had the same problem and the wheel wobble was indeed caused by a sticking caliper. I replaced both front calipers which is an easy DIY job with some refurbished ones from Bigg Red at a very reasonable cost and the car has been fine ever since. I hope this is of some help to you

[Zedbedee]

Sticky calipers cause wheel shake. They also cause very hot wheels so if one wheel is much hotter than the others you have a sticky caliper for sure. Rebuilding calipers is not difficult and can be very satisfying. All the parts are available for not much money from Big Red and allthough the pistons can and will corrode the bores tend to stay fairly pristine.
I found the longest part of the job was cleaning up the caliper housing.

[philip43]

I had this problem too, and I knew it was the brake caliper. How? Well, a tell tale sign is a greater amount of brake dust on one wheel in comparison to the other. Another is that the steering pulls to one side, whichever side is sticking. And yet another is that after driving and applying the brakes, the affected wheel feels hotter to the touch than the unnafected wheel. But be careful, as the wheel can get hot, depending on how badly the caliper is sticking!! Another sign, (yes, more!!) is fuel consumption. I drive a 3.0, and prior to fixing my problem I was getting 24.7 mpg. I am now getting 32.7 mpg, at least, according to the OBC I am!! If you have the above symptoms, then it more or less rules out suspension problems, although they can be present as well. HTH

[Mike Fishwick]

Yes - a sticky caliper will cause heating and pulling to one side - but not the short period of violent shaking which started this discussion.

Diagnosis via internet forum is usually ineffective and expensive, but I would put my money on the wishbone rear bush, tyres, dampers, or ball joints.

There is no substitute for getting under the car and giving things a good looking at and shaking around!

[philip43]

Yes - a sticky caliper will cause heating and pulling to one side - but not the short period of violent shaking which started this discussion.

Diagnosis via internet forum is usually ineffective and expensive, but I would put my money on the wishbone rear bush, tyres, dampers, or ball joints.

There is no substitute for getting under the car and giving things a good looking at and shaking around!

When mine was sticking, I experienced a juddering in the steering, and originally put it down to the tyres. It was infact a buckled brake disc due to the heat being generated with the sticking brake caliper. What i'm saying is that although the suspension can cause juddering in the steering, when it starts it won't rectify itself, whereas a sticking brake caliper can become free again, and therefore the juddering dissappears! This appears to have been what happened according to the OP!!

[philip43]

Diagnosis via internet forum is usually ineffective and expensive, but I would put my money on the wishbone rear bush, tyres, dampers, or ball joints.

My thoughts entirely, but then, i'm not diagnosing the problem, and I don't think anyone can over the internet. What I can do though, is give my personal experience to others in the hope it sheds some light on their problem, and at least, if nothing else, eliminate a possible cause. I wouldn't put my money on it being anything in particular, without having experienced the actual problem myself.

[Mike Fishwick]

As Inspector Clouseau put it - 'I suspect everyone, and I suspect no-one!'

The cause could be any single thing, or a combination of things and circumstances.

Trying to diagnose a fault using other people's guess and experiences is never going to be an accurate process - you have to get in there and look at things.

[philip43]

As Inspector Clouseau put it - 'I suspect everyone, and I suspect no-one!'

The cause could be any single thing, or a combination of things and circumstances.

Trying to diagnose a fault using other people's guess and experiences is never going to be an accurate process - you have to get in there and look at things.

Do you read other peoples posts Mike?
Do you even read your own?

[Mike Fishwick]

Sorry - I don't understand what you are getting at - keep it simple please.

[philip43]

Sorry - I don't understand what you are getting at - keep it simple please.

Sorry, but even I can't do 'that' simple.

[z3bedee]

Why is this developing into an argument? I think every possible cause has been mentioned and checking and eliminating each one is easy and totally free. personally I can't wait for the result but keep it up fellas its very entertaining

[c_w]

Yes - a sticky caliper will cause heating and pulling to one side - but not the short period of violent shaking which started this discussion.

It can and it did to mine to the point it felt like someone was hitting the wheel with a hammer or it was falling off! I've never known judder/wobble through the steering like it, it started like wheel balance wobble but turned into a violent banging shake at slow motorway speeds. The disc survived and was fine when the caliper was freed. I used the flat blade in the tool kit to lever the caliper slightly from the disc and drove home trying not to touch the brakes.

There is a chance in the OP's instance that the caliper unstuck itself with some harder braking and came off the disc enough and/or the brake cooled enough to carry on fine.

It's even less likely that a fixed mechanical part like a ball joint, bush or damper would suddenly start then stop causing the judder IMO.

[g8jka]

Yes - a sticky caliper will cause heating and pulling to one side - but not the short period of violent shaking which started this discussion.

It can and it did to mine to the point it felt like someone was hitting the wheel with a hammer or it was falling off! I've never known judder/wobble through the steering like it, it started like wheel balance wobble but turned into a violent banging shake at slow motorway speeds. The disc survived and was fine when the caliper was freed. I used the flat blade in the tool kit to lever the caliper slightly from the disc and drove home trying not to touch the brakes.

+1

I had this recently too, the wheel judder was horrendous and it was purely because my caliper was stuck. I could tell by looking for the symptoms listed above, loads of brake dust just on that wheel, red hot to touch and wheel not spinning as freely as the others. I didn't get the pulling to the side but have now freed the caliper and guess what ... the juddering has gone. So, in my own experience it can infact cause the short period of violent shaking which started this discussion.

[philip43]

When my brake caliper 'siezed', the brake pads were being applied to the disc. This is what caused the steering shudder. As I drove on, the caliper was still siezed, but the brake pads, as a result of still being applied against the disc, wore down to the point were they were no longer binding against the disc. This is why the steering shudder dissappeared. It's a common fault on the 3 series, and the Z models, as they both use the same calipers. My fix was to get a good second hand caliper in a breakers yard. Problem solved.

[uggers2k]

Hi guys,

Many thaks for all your comments. The vibration has not occurred since and I even took it up to over 100mph (on a private road) and have been braking sharply etc and nothing totally fine.

Car is booked in on Wednesday, so will reply with a diagnosis.

Thanks

[philip43]

Hi guys,

Many thaks for all your comments. The vibration has not occurred since and I even took it up to over 100mph (on a private road) and have been braking sharply etc and nothing totally fine.

Car is booked in on Wednesday, so will reply with a diagnosis.

Thanks

Are you just bringing it in for a report on the fault?