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steering vibration when braking

Posted: Thu Sep 20, 2007 7:22 pm
by subidoo
I've got an '89 Lseries touring wagon MPFI manual with 3" lift. When I brake I get quite violent shudders or vibrations through the steering wheel. They are worse when braking from higher speeds. Doesn't come through the brake pedal. I've replaced all the bushes in the front suspension with urethane (sway bar, lower control arm and radius rod bushes). No constant vibrations when driving along although sometimes I do get a vibration in the steering wheel but only minor and doesn't last long. There's also a bit of a rattling noise , like something is loose, coming from the front end. I've looked and looked but can't find what it is.

I'm thinking warped disk rotor, but I would expect to feel that through the brake pedal.

Any ideas ? Wanted to have a go at it this weekend.

Also noticed that the gearbox cross member bushes are flogged. Can you get urethane ones or are standard rubberones OK? Any recommendations where to get them from?

Thanks for any advice.

Posted: Thu Sep 20, 2007 7:37 pm
by subybrumby
Don't overlook castle nut and cone washer in front wheels. Castle nut needs to be extra tight and cone washer may be worn. If the washer is worn or the nut not tight, you get all sorts of sounds and wobbles. Can sound like a disc brake pad has come loose and is being chewed up in the works. I replaced the nuts and washers on my brumby and finally shut them up. Got sick of people staring at me when I pulled up at the lights..thats how much noise they can make.

The washer may look alright, but if its worn, it crunches about..

Posted: Thu Sep 20, 2007 7:52 pm
by Suby Wan Kenobi
Sometimes i get a vibration through the front as you describe and it turns out to be the pressure in the front tyres is not the same. but it can be a rotor of the hub nut.

Posted: Thu Sep 20, 2007 7:54 pm
by theclick
Suby Wan Kenobi wrote:Sometimes i get a vibration through the front as you describe and it turns out to be the pressure in the front tyres is not the same. but it can be a rotor of the hub nut.
Thats what it was for me. When i started applying to brakes from ~100kmh, i would get a wooble in the wheel of about 10rpm. Turns out it was a dodgy tyre.

It also removed what i Thought was torque steer, but was infact the crappy tyre leading me off at initial take off

Posted: Thu Sep 20, 2007 7:55 pm
by AlpineRaven
or tyre offset - get the wheel balanced - does it happen in low or high speeds?

Yeah it can be warped brakes even if you cant feel it.
Cheers
AP

Posted: Thu Sep 20, 2007 8:28 pm
by keppler
check the disks i have replaced both now with same fault described

lift whole front end up support it chock rear wheels and start up and put in 1st and let out clutch check disks now for how true they are running

Posted: Mon Sep 24, 2007 10:07 pm
by plucky
Check your castor with the lift kit.

Posted: Mon Sep 24, 2007 10:12 pm
by Matatak
90% of the time it means ur front discs are warped..so check em out and if they ened it get them skimmed shuldnt be more than 50..and no u wont feel it thru the brake pedal.
when its front discs it comes thru steering and when its rears u have to try n feel it thru the seat and body of the car basically lol

Posted: Sun Mar 04, 2012 4:29 pm
by Davodello
I have a brumby with a EJ22 motor with exactly the same problem, the run out in the left disc is .015" the right is .008". The strange thing is the brakes are good at low speed and then from 100k's the vibration is really bad after the brakes are warmed up. New seals in master cylinder (due to leak) and I notice that there is a slight pulse in the pedal but if I keep an even pressure on the brake the pedal very slowly keeps moving in toward the floor. Rear brakes adjusted as per book I am thinking new rotors and a strip down of caliper's any thoughts??
Dave

Posted: Sun Mar 04, 2012 4:54 pm
by thunder039
could be something as simple as needing the disc machined, happened to me not long ago in my forester

Posted: Sun Aug 03, 2014 11:09 am
by preno
Old thread I know but same question.

I have a shudder when braking.

I first thought warped disc but these are fairly new discs. I replaced LHS disc as visually you could see the disc pushing the brake pads in and out. The new disc is doing the same thing.

What should i be looking at next? hub?

i pulled the bearings out and they look fine. if the spacer between the bearings was worn would this cause this kind of movement?

CV shaft was also replaced a few months ago.

I need some ideas before i start replacing everything on the front end..

Cheers,

Matt

ps. its is an 88' Brumby

Posted: Sun Aug 03, 2014 8:03 pm
by El_Freddo
Could be the hub is bent, I've seen the same thing on my L series - bent front left hub. I have no idea how I did it!

Cheers

Bennie

Posted: Sun Aug 03, 2014 10:01 pm
by Brumby Kid
Wheel nuts not done up tight (you would be suprised)
Or my favourite, which caused this problem for me was the mechanic not doing the castle nut up tight enough on the CV. Was pissing me off, and thought my whole hub was going to have to come off.
Started to take everything off the front left until i noticed the castle nut was finger tight. this meant the hub was loose and the discs/ hub/ calipers could all move.
That was the last time I went to that mechanic.

Cheers Cam

Posted: Mon Aug 04, 2014 5:29 pm
by preno
Cheers guys,

wheel & castle nut all torqued up to spec.

thinking when i get time i will swap left and right hubs and see if the problem moves sides. should help at least isolate the issue to a specific area.

Posted: Sat Aug 09, 2014 5:00 pm
by preno
today i swapped disc and hub from LHS to RHS. also measured disc run out before and after swapping from either side.

RHS showed to be within spec even with the LHS hub & disc on. LHS was over spec before and after swapping.

this tells me that the discs are not warped & hub not bent..

next job will be replacing bearings & bearing spacer i think.