92 L series brake shudder

92subbie · Post by **92subbie** » Wed Mar 03, 2010 9:08 pm

Hello all,

I am having some issues with my 1992 L Series wagon with severe brake shudder and steering wheel wobble at speed. I have recently had the discs machined as I suspected warped discs, and didn't make a difference. My pads weren't badly worn so I didn't replace the pads. Should I try replacing them?

I also took it to a suspension shop and they informed me that my steering rack was pretty loose and may cause it to be oscillating at high speeds. So I pulled it out, replaced it with another one and adjusted the gear back lash and hasn't seemed to make any difference.

Has anyone on here experienced the same thing and how did they go about eliminating the problem?

Regards,

Leigh

holden26 · Post by **holden26** » Wed Mar 03, 2010 9:33 pm

have you checked your wheel bearings?

YouTube · Post by **El_Freddo** » Wed Mar 03, 2010 9:37 pm

G'day Leigh.

Sounds like a tyre may have thrown a weight. You'd be surprised how a simple little thing like this can create such a problem. Try changing your tyres front to rear and vise versa - that should change the problem tyre and the vibration to the rear.

If it does, have the tyres re balanced if they're worth the little bit of money it would cost for this service. If they're close to renewal, either put up with it longer or replace them.

All the best.

Cheers

Bennie

RSR 555 · Post by **RSR 555** » Wed Mar 03, 2010 9:46 pm

Sounds like a tyre issue. I had a similar problem and it turned out that the tyre was going egg shape

I'd have the tyres checked and balanced and while you're there, just check your wheel bearings before you take the wheel off the car.

92subbie · Post by **92subbie** » Wed Mar 03, 2010 9:50 pm

I have been told my wheel bearings are fine. I have had the drivers side ones out before and they felt good.

So out of balance wheels can also cause brake shudder?

I too have been told (on another set of wheels and tires) that they began going "egg" shape...

Looks like for now its off to get balanced and aligned and go from there.

Cheers!

drof351 · Post by **drof351** » Wed Mar 03, 2010 10:06 pm

Hi, Were your discs machined on or off the vehicle? Maybe bent hub? Have you got access to a dial gauge to check the run out?

92subbie · Post by **92subbie** » Thu Mar 04, 2010 9:35 am

They were machined off the car. No I don't have access to a dial gauge. What would cause a bent hub?

someguy · Post by **someguy** » Thu Mar 04, 2010 10:02 am

92subbie wrote: What would cause a bent hub?

Wheel nuts being done too tightly or not evenly.

Lots of mechanics get this problem because the guns they use to put the wheel nut back on has too much pressure/force.

Its happened to me before. Also had wheel nuts stripped because of the sheer force/speed those guns pull them off.

Most "respectable" mechanics will do them by hand these days.

If I ever leave my car with a mechanic (I try not too these days) I make sure they do the wheel nuts back up with a brace.

discopotato03 · Post by **discopotato03** » Thu Mar 04, 2010 12:24 pm

In my experience L's are very sensitive to tyres running out of round and wheel balance . I think because 13" tyres are getting thinner on the ground its hard to find good ones . The cheapest nastiest Chinese tyres are rubbish so avoid them or at least go one price range up with them .

I get on well with my tyre people , three gens of us have used them , and I watch them balance my wheels all the time . I have seen the junk tyres wobble all over the place or a times way too much weight needed to get an acceptable "balance" .
If your rims are an unknown quantity get them to spin them up without a tyre and you'll see straight away if they dont run true .

A .

RSR 555 · Post by **RSR 555** » Thu Mar 04, 2010 1:54 pm

92subbie wrote:So out of balance wheels can also cause brake shudder?

On some cases yes but I'd get the tyre shop to just check over the whole front suspension parts to confirm nothing else has gone wrong. The other thing you can check is the CV nuts are tight (you should hear creaking sounds from the front but not all the time) that can cause it too.

92subbie · Post by **92subbie** » Thu Mar 04, 2010 4:54 pm

RSR 555 wrote:On some cases yes but I'd get the tyre shop to just check over the whole front suspension parts to confirm nothing else has gone wrong. The other thing you can check is the CV nuts are tight (you should hear creaking sounds from the front but not all the time) that can cause it too.

Yes I occasionally hear a creaking sound, at low speed... I thought that may be a dodgy cv but the suspension shop told me the cv's were fine.

I have swapped wheels front to back and still the same issue. I then tried another lot of wheels that I have and still the same issue.

I did notice that there is still play in the steering rack. Worth getting it rebuilt?

tony · Post by **tony** » Thu Mar 04, 2010 5:24 pm

check the tie rod ends, a bit of looseness there can cause wobble. if you stab the brake pedal does that stop the wobble?
Holden did a test some years ago and found that machining brake disks on car was far more reliable than off car, less inaccuracy.
also can't hurt to check wheel bearings, jack wheel off ground, and place hand on bottom of tyre and try to lift/rock wheel, if it moves at all there is a problem. then place hand on front of tyre and wriggle side to side, this will pick up tie rod end looseness.

Morcs · Post by **Morcs** » Fri Mar 05, 2010 3:36 pm

check the tie rod ends, a bit of looseness there can cause wobble.

I totally agree with this also check the rack itself and ball joints

Another thing may not be an issue with a standard motor etc
is check the rotors for cracks splits etc
Under high temps these have a tendancey to crack

92subbie · Post by **92subbie** » Fri Mar 05, 2010 5:31 pm

like i have mentioned above, the rack itself definitely feels loose still (even after adjusting the back lash) is it worth spending the money on getting it refurbished?

I noticed today that there was a deep "clicking/rubbing" sort of sound coming from the front end... I'm beginning to think this may be something a little serious....

rtcb65 · Post by **rtcb65** » Fri Mar 05, 2010 8:12 pm

Are your castle nuts done up real tight. I have had the experience of them lose and i heard a noise and my wheel wobble slightly which aloud the disk to wobble in the calipers .

YouTube · Post by **El_Freddo** » Fri Mar 05, 2010 8:50 pm

G'day 92subbie,
If you can wait til next wednesday, I'd be happy to drop over and check it out for you. I'm a certified backyard mechanic

If I get my crap sorted on sunday (got a project to sort) I could drop over then...

PM sent.

Cheers

Bennie

RSR 555 · Post by **RSR 555** » Fri Mar 05, 2010 11:14 pm

rtcb65 wrote:Are your castle nuts done up real tight. I have had the experience of them lose and i heard a noise and my wheel wobble slightly which aloud the disk to wobble in the calipers .

This is where I was leading too.. I think your castle (Outer CV) nut may not have been done up right. You may be best waiting to Bennie can drop over and show you the deal with the front end parts. If you can't wait then I'd look at removing your castle nut and checking the taper washer. 9 times out of 10 I find there is a lip on the top of the taper and when you do the castle nuts up tight it gets locked up on the lip and doesn't push the taper washer in correctly. File off the lip and reassemble all parts and do the castle nut up has hard as you can. To see if this is the problem, just follow the above advice on checking your wheel bearings.

YouTube · Post by **El_Freddo** » Sat Mar 06, 2010 7:15 am

Yeah good idea on the castle nuts. Very common. I'll pack the 36mm socket and half inch breaker bar

That'll sort them out

Cheers

Bennie

92subbie · Post by **92subbie** » Sat Mar 06, 2010 4:45 pm

PM sent. cheers

92subbie · Post by **92subbie** » Mon Mar 15, 2010 8:01 pm

ok so after a kind visit from Bennie last week (and after what we thought was majority of problem solved...) it is back making horrible noises. I am putting my money on a f'd CJ-joint but I made a recording of the noise so you guys can witness it for yourselves....

This was recorded over the weekend whilst i was driving to Geelong. The recording starts off at 100km/h and then i think i start to slow down... but for reference the noise does seem to stop when the brakes are applied.

Heres the link to have a listen:

http://www.youtube.com/watch?v=Cyk7sDCiuUA