Topic: Wobble when braking hard... (Read 3188 times)

JasonH · « **on:** 13 December 2006, 21:10:04 »

Need some expert advice and pointers on this...

Recently my car has developed a steering wheel wobble when braking hard at higher speeds. You don't get it round town but do get it above 50mph for example when coming off a motorway.

Doesn't seem entirely consistent I think some road surfaces may set it off more than others. Perhaps slight steering left or right triggers it - not sure.

It doesn't appear to be brake shudder, it's more a left right wobble of the steering wheel.

There's no pull to the left or right; the car stops in a straight line.

Put new wishbones on 6 months ago. As far as I can tell the bushes still look OK, but these weren't genuine wishbones (although they were off a major Ebay supplier).

There are no clonks or thunks.

I've have a good poke around underneath and perhaps the wishbone bushes are more compliant than they should be - but I'm not sure exactly how stiff they should be when new.

I've had the wheels balanced - which has reduced vibration at high speeds - but it has made no difference to the wobble.

What do I check? And how?

Based on the symptoms, wishbones? or steering idler? anti-roll bar bushes? or something else? Help!

Kaycee · « **Reply #1 on:** 13 December 2006, 21:30:24 »

tell me you did have the steering geometry realigned

JasonH · « **Reply #2 on:** 13 December 2006, 21:36:31 »

When I put the wishbones on it was fully aligned, front and rear camber and tracking.

All set dead on and had even tyre wear for about 10k miles, it has gone off now though. Fronts wearing on the inner edge.

B52 · « **Reply #3 on:** 13 December 2006, 21:47:57 »

warped disc?

JasonH · « **Reply #4 on:** 13 December 2006, 21:54:01 »

I must admit I've not checked the disks - but I don't really get much back through the brake pedal.

I'll add disks to my list of things to check at the weekend.

JamesV6CDX · « **Reply #5 on:** 13 December 2006, 23:19:30 »

When braking hard from about 80mph, my V6 has a VIOLENT steering wheel wobble, it has been there for only a few days.

although - the brakes also feel less effective, I don't feel like I've got as much trust in my brakes, it seems like more pedal effort is required to stop the car, and stopping quick from high speeds nowhere near as good as it should be.

Kaycee · « **Reply #6 on:** 14 December 2006, 07:14:32 »

Jason
To be quite honest you may well have a problem with the wishbones again my first set lasted just 9 month and i did have similar problems to you i discounted the arms as they ad not been long changed but when it came down to it it was the arms. if the camber goes out of spec because of the bushes that causes the wobble and vibration as the setting becomes dynamic (changes settings to road conditions) i would also check the discs as it may be at a certain tempreture that this problem arises it may even be a sticking caliper. but if as you say tyres are noticably wearing on inside i would seriously look at the arms again it was the learned guys on this site that told me about aftermarket arms The upshot is dont buy em unless you selling car.
Robert

JasonH · « **Reply #7 on:** 14 December 2006, 09:16:30 »

Kaycee I fear you might be right - my instinct is wishbones.

The genuine ones are £180 each though. The ones I fitted came with a 12 month warranty.... we shall see.

I think I'll get some more and then take the old ones off and have a look. If they're bad I'll have some new ones to put on.

tunnie · « **Reply #8 on:** 14 December 2006, 09:48:15 »

Quote

I must admit I've not checked the disks - but I don't really get much back through the brake pedal.

I'll add disks to my list of things to check at the weekend.

I had this exact same problem!! Around 50 or so it tended to be quite bad, but never did it around town.

I had warped disc's although the current pads were the right size, i think the previous ones where wrong and damaged the discs.

I fitted brand new Vx discs and pads, they come as a set (£66 on trade club). Fixed it straight away, along with a brake fluid flush and change, it made a vast difference.

Richard A · « **Reply #9 on:** 14 December 2006, 12:25:09 »

I have just had to change front discs and pads because of this very fault. Tends to affect automatic's more as drivers use the foot brake rather than the handbrake when at a standstill, the heat transfers between pads and discs, this causes hot spots on the disc and they can and do warp.
regards

TheBoy · « **Reply #10 on:** 14 December 2006, 13:33:59 »

Warped discs, worn wishbone bushes, worn track rod ends, worn idler can all cause this wobble.

JasonH · « **Reply #11 on:** 14 December 2006, 19:43:23 »

Thanks for the advice. When I find the fault I'll report back.

B52 · « **Reply #12 on:** 14 December 2006, 20:39:38 »

Quote

I have just had to change front discs and pads because of this very fault. Tends to affect automatic's more as drivers use the foot brake rather than the handbrake when at a standstill, the heat transfers between pads and discs, this causes hot spots on the disc and they can and do warp.
regards

i got caught out by this on my last omega. and i warped 3 sets of pattern discs before i gave up on them and got genuine vauxhall. front discs on an auto have a hard life

BazMV6 · « **Reply #13 on:** 15 December 2006, 09:13:54 »

Interesting stuff. I have the same problem, at the same speed (50) under braking. Thought it was down to wheel balancing, and was putting that off until I get the new tyres I desperately need. But if that were the real reason then it would surely wobble at 50 whether braking or not? Sounds like I need to replace the discs - and maybe start using the handbrake more...

Where's the best place to get this sort of work done? This is my first privately-owned car after many years of company (Vauxhall) driving - and I vowed I would never go near the local Vx main dealer if it were my own car. Any recommendations in MK/Northants area?

Baz.

Andy B · « **Reply #14 on:** 15 December 2006, 09:47:34 »

Quote

Interesting stuff. I have the same problem, at the same speed (50) under braking. Thought it was down to wheel balancing, and was putting that off until I get the new tyres I desperately need. But if that were the real reason then it would surely wobble at 50 whether braking or not? Sounds like I need to replace the discs - and maybe start using the handbrake more...

Where's the best place to get this sort of work done? This is my first privately-owned car after many years of company (Vauxhall) driving - and I vowed I would never go near the local Vx main dealer if it were my own car. Any recommendations in MK/Northants area?

Baz.

Buy Vauxhall Trade Club discs & pads for about £70 and fit them yourself. It'll take you half an hour a side, they are that simple. Unbolt the caliper & move to one side, remove a small 6mm countersunk screw from the disc hub - & that's it.

tunnie · « **Reply #15 on:** 15 December 2006, 12:59:26 »

Quote

Interesting stuff. I have the same problem, at the same speed (50) under braking. Thought it was down to wheel balancing, and was putting that off until I get the new tyres I desperately need. But if that were the real reason then it would surely wobble at 50 whether braking or not? Sounds like I need to replace the discs - and maybe start using the handbrake more...

Where's the best place to get this sort of work done? This is my first privately-owned car after many years of company (Vauxhall) driving - and I vowed I would never go near the local Vx main dealer if it were my own car. Any recommendations in MK/Northants area?

Baz.

Well since your up the road m8 from my regular home, i could do it for a small fee

Serisouly though its very satisfing to do jobs yourself, you also know its been done right! Ask for some quotes but i did mine for £66 + vat, this was for GM Discs and Pads (you get a set of pads with the Disc set)

I changed mine with guidence from TheBoy on his driveway, took about an hour per side. But this was my first time, so would be the same again. I do have photos of me doing it, and was going to make it into a guide but never got the chance. Think i'll post them up anyway for reference.

Richard A · « **Reply #16 on:** 15 December 2006, 13:31:52 »

Sorry ! I omitted to say the discs which were taken off were only 9 months old (none GM), the new discs and pads were £94-00 (list price) from a Vauxhall dealer, cheaper with Trade Card.
Braking from any speed now perfect.
regards

tunnie · « **Reply #17 on:** 15 December 2006, 14:14:59 »

Quote

Sorry ! I omitted to say the discs which were taken off were only 9 months old (none GM), the new discs and pads were £94-00 (list price) from a Vauxhall dealer, cheaper with Trade Card.
Braking from any speed now perfect.
regards

I forgot they were £94 retail, so down to £66+ vat is a good price

Baz, you should be able to get the discs and Trade club prices with a little help from TheBoy

BazMV6 · « **Reply #18 on:** 15 December 2006, 19:22:54 »

Thanks for info - used to do my own work - but that was 20 years ago... Didn't much enjoy scraping my knockles on the drive even then...

Tunnie - is your Dad's name Nigel, by any chance??

tunnie · « **Reply #19 on:** 16 December 2006, 01:01:37 »

Quote

Thanks for info - used to do my own work - but that was 20 years ago... Didn't much enjoy scraping my knockles on the drive even then...

Tunnie - is your Dad's name Nigel, by any chance??

This is unreal, your the second person on this forum who used to work with my Dad!!

Another user here called AllenM used to work with my Dad, when Unisys was called Burroughs!

I remember him mentioning a guy called Barry!! - Unreal!!!!

I am going home after the weekend so i'll mention it to him

JasonH · « **Reply #20 on:** 16 December 2006, 16:31:43 »

Found the problem.

Kaycee hit the nail on the head, The Boy was right too.

The vertical bush (at the rear) on the passenger side wishbone has torn. It was only really visible with the car jacked up and the wheel off.

A pair of new wishbones and full geometry it is then.....great!

News:

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