Steering Wheel Wobble Under Braking

[rincewind]

Hi all,

I've noticed recently at 50+ mph there is a perceptible steering wheel wobble under braking. At 114k on the clock, I'm thinking front suspension. Any thoughts as to what it might be?

Thought: I have unevenly worn front tyres since Lexus did a 4 wheel alignment almost 2 years ago. I never used to get uneven wear before this - could that be a cause of the above? I have read that the Lexus alignement is not the best, they have the wrong settings (seem to remember reading that somewhere on this forum).

[lexus22]

One (or both) of the front discs are giving you this problem, assuming that they have not been changed recently, then you will need to change the pair. (£40.00 each from Euro car parts- Pagid discs) Worth checking the brake calipers are not sticking as if you fit new discs and one of the calipers is sticking then the disc will warp again!

[andyk134]

Strange as mine has just started doing the very same thing and a bad vibration at around 50 as well. Going to get it checked out at the weekend

[rincewind]

Both front discs are new - Lexus OEM from the dealer. No sticking calipers either. The problem was, IIRC, there before the discs were changed but has got worse recently. I'm suspecting suspension links worn along with wheel alignment, as the front tyres are unevenly worn, the n/s being quite markedly uneven. Just got two new front tyres, gonna get Lexus to check the suspension and then I'm going to get a full 4 wheel alignment done. Here's hoping...

[Stuno1]

Wheel balance or warped discs i imagine. Get allignment done then look at the discs.

[ChrisIS200SportTTE]

I'd suspect sticking calliper. A bad alignment shouldn't give serious judder under braking, it can, but if it's bad I wouldn't think it's this. Also if your alignment was so far out it causes steering judder under braking you car would be pulling everywhere and feel like a boat lol! If it's warped discs then you need to find out why the disc(s) warped, a sticking calliper will do this.

A wheel balance issue won't show itself under braking, that will show itself as a steering wobble in a certain speed window, normally 45-60mph.

First thing I would do if I were you would be to take the car for a spirited 15-20 minute drive. As soon as you get home jack the car up. Temperature of the wheels should be a constant, front two slightly warmer than the rears but not hot. If one wheel is very hot suspect a stuck calliper on that wheel. The front wheels should spin freely and easily buy hand when jacked up, If they don't, then it's a stuck calliper. Also when callipers sieze on strongly you can't help but notice the smell of burning brakes as you get out of the car.

Another thing often overlooked that causes judder under braking is the rear lower control arm bushes. If these are perished it'll judder under braking.

[ChrisIS200SportTTE]

I missed the post where you said it's not calliper, apologies.

If you have accelerated front inner tyre wear and juddering under braking I really would think this'll be you lower control arm bushes.

Don't let Lexus do your alignment. Get WIM to do it. They'll also tell you what's causing the juddering. I really do suspect the bushes.

[rincewind]

Thanks Chris, at 114k miles I'm with you on the lower control arm bushes. Question - are these part of the front or rear suspension?

[ChrisIS200SportTTE]

Front as that why it makes the steering wobble and they are notorious for perishing. I've had to replace them on both IS's I've owned because of similar wobbles, misalignment problems.

http://www.lexusownersclub.co.uk/forum/topic/81690-completly-bushed/

[rincewind]

WIM are a bit far for me - 2 1/2 hour round trip. I was looking at this place which was spoken highly of on BMW5.co.uk:

http://www.perfect-touch.co.uk/services/4-wheel-alignment-hertfordshire/

[rincewind]

Chris, having looked at the completely bushed thread, where did you source the bushes from?

[ChrisIS200SportTTE]

eBay... £18 each.

You can't buy OEM bushes from Toyota/Lexus unless you buy the whole arm at £300 per arm!!!

[ChrisIS200SportTTE]

Also whilst the bushes are perished Its impossible to do an alignment. You'll literally drive off the ramp and back up onto the ramp and the alignment would've changed.

[andyk134]

Hi,

Mine turned out to be a sticking caliper, so a new one is being done and a skim of the disc. Hopefully that will sort it out!

[ChrisIS200SportTTE]

Hi,

Mine turned out to be a sticking caliper, so a new one is being done and a skim of the disc. Hopefully that will sort it out!

Most common cause of brake judder above 50mph is a sticking calliper on these cars. Not surprised mate lol.

[litimag]

I have been having very similar issues, bad judder at braking over 60ish. I know the front discs are scored, it showed up as an advisory at the MOT and i have had a look at them on the ramp.

So is that the full reason for the judder? or maybe a sticky caliper too? No obvious brake smell from the car even after a run, but if i need a new caliper (God forbid), what would be a reasonable price?

[rincewind]

Hi

It wont be scored discs causing the wobble. See above for possible causes. I changed both my front discs recently for OEM Lexus ones, total cost for discs and pads was £230. That was for doing it myself. Quite an easy job but I would make sure you have a breaker bar to undo the caliper bolts, £13 on amazon.

[rincewind]

That was for both discs btw.

[lexus22]

Update on mine. Had new n/s hub and bearing fitted with yet another new disc as well, noticed a slight steering judder when applying brakes straight away but in a week has got worse. Braking from anything above 55mph the steering shakes like mad.

Neither of the front (or back) wheels are getting hot. Took it back to garage this morning and car was put on the rollers where the brakes/calipers were checked, the LED lights on the screen were not stable when the front wheels were in the rollers, apparently the two bands of LED lights, one for each wheel should stay lit the same amount and be constant. First of all the LED's for the n/s wheel were not stable, moving slightly left and right on the screen but the o/s led's were showing stable, but after a couple of minutes the o/s LED's started to fluctuate as well. Mechanic has offered to take the car for a week to see if he can find the problem as he is as baffled as me! (The calipers have been rebuilt by the way)

Would you think that those lower bushes could be the problem??

New n/s hub, pads, disc, brake hose, caliper rebuilt, o/s pads, disc, caliper rebuilt ...so far!!

[rincewind]

I'm now looking to get the bushes all checked for mine as that's probably the cause. I can't find anyone to replace just the bush though. Bush £18, Lower control arm inc. bush £180. That's a massive difference especially when X2 for both sides. Grrrr....

Will make sure they are knackered before going down that route.