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Shuddering problem.

Started by _73LJWhiteSL_ , Jul 16 2006 09:54 PM

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29 replies to this topic

#1 _73LJWhiteSL_

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Posted 16 July 2006 - 09:54 PM

gday all,

I have this problem with the brakes on the Torana at the moment, that sometimes when i put my foot on the brakes, i get a shuddering feeling and vibration that travels up the steering wheel. However it doesn't happen all the time...

Any ideas?

Steve

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#2 _LX8VD69_

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Posted 16 July 2006 - 10:07 PM

are your discs warped? could wheel bearings do this as well?

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#3 _munro_

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Posted 16 July 2006 - 10:41 PM

what ^ said or contaminated brake pads

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#4 _73LJWhiteSL_

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Posted 17 July 2006 - 12:13 PM

I don't think it is discs because they are fairly new slotted XU-1 discs but i can get them checked out. Also the pads are also fairly new.

I have never replaced the wheel bearings i guess i could look into that.

thanks for the suggestions guys... i will have a look at it. :spoton:

Steve

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#5 _lx5008_

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Posted 17 July 2006 - 12:35 PM

are the slotted rotors kangaroo paw pbr type, ive had a few faulty sets lately.
you can tell buy the hot spots on the rotor its self in between the slots.

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#6 _73LJWhiteSL_

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Posted 17 July 2006 - 01:09 PM

Can i ask what do 'hot spots' look like?

I got the rotors from dattoman back last year sometime. Not sure of the brand.

Steve

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#7 _lx5008_

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Posted 17 July 2006 - 01:17 PM

they look like just a heat mark, you will know what i mean when you look
at them. can you also hear a noise when they shudder.
best thing is just check any bluey type colour marks between the slots
cheers graham

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#8 _73LJWhiteSL_

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Posted 24 July 2006 - 02:52 PM

Well it looks like i might have a solution. Haven't had a chance to look at the car till today.

I pulled the wheels off and had a look at the rotors. They looked fine, no marks of any kind i could see other than the usual cirular marks from the pads.

So i pulled the pads out. Well well well... the anti squeal shims on the drivers side were backwards. I scuffed the pads up on the concrete and took it for a drive to 'bed' the pads in again. It doesn't appear to be shuddering anymore, but i will see how we go over the next few weeks. :spoton:

Steve

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#9 _timbotorrie_

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Posted 24 July 2006 - 06:50 PM

check to see how tight your wheel bearings are if changing the pads around doesnt work mate!

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#10 _73LJWhiteSL_

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Posted 05 November 2006 - 01:14 PM

Gday all,

sorry to dig up such and old post, but its taken me this long to find the time to actually check the brakes out.

According to the little gauge I borrowed off my mate, my discs have 0.4mm run out. Well the drivers one does at least. This was all i bothered to measure.

So that answers it. My 12 month old, 20,000 Mile old, disc rotars are warped. I have no idea how this has happened, as they started doing it long before i took them to a race track.

Steve

Edited by 73LJWhiteSL, 05 November 2006 - 01:24 PM.

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#11 dattoman

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Car:LX SS , 76 Cadillac , 3 x dattos
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Posted 05 November 2006 - 08:40 PM

Rotors rarely warp
Runout could be in the bearings or vibrations can be could be suspension related.
Since you have checked and found a .4mm runout I'd suggest youreplace the bearings. Have the discs then very lightly skimmed whilst attatched to the hubs (on the new cones) and refit
While its apart I'd be checking the pistons in the calipers are free and retracting properly

Solid rotors are not kangaroo paw by the way..... only vented could be as KP is a vent and pillar design
DBA make KP not PBR
Those 2 statements refer to previous posts made mid year (my first read of this thread)

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#12 _73LJWhiteSL_

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Posted 08 November 2006 - 08:07 PM

Thanks for the thoughts Neil.

As best I can tell from my records it appears the front bearings have never been changed and the car has just clocked over 120,000 miles. I think i might just take the rotars in to get machined and stick new bearings in as you have suggested. And get the calipers checked out or maybe just rebuilt.

Steve

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#13 _Oldn64_

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Posted 08 November 2006 - 09:36 PM

I would do the bearings first. As Neil has stated disc rarely warp. Also as Neil has pointed out You do not have KP rotors Steve. I would also then test runout again once the new bearings are in place.

Cheers

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#14 _CHOPPER_

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Posted 08 November 2006 - 10:40 PM

At $40 for new bearing kits for both sides and probably $20 to get both discs machined, it wouldn't hurt to spend the extra and only do the job once. If there isn't any runout in the disc, you wouldn't even be able to measure the lick they remove off the disc surface.

Edited by CHOPPER, 08 November 2006 - 10:40 PM.

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#15 Stedz_lc

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Posted 09 November 2006 - 05:22 PM

I disagree that disc rarely get run out! I work in a place where 60% of our work is brake n clutch n id say every second falcon n commodore has run out in the rotors, major shudder/pulsation jus my 2cents worth from experience!
Cheer
Stedz

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#16 _CHOPPER_

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Posted 09 November 2006 - 07:46 PM

Yes, but they have ventilated discs, the LJ has solids. Nevertheless, I still say to spend the extra and do it once.

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#17 _keith1962_

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Posted 09 November 2006 - 09:28 PM

Hi guy's

Could it be the shocks????????????

cheers Keith

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#18 TerrA LX

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Posted 09 November 2006 - 09:40 PM

rack or tyre pressure?

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#19 dattoman

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Posted 10 November 2006 - 01:01 AM

I disagree that disc rarely get run out! I work in a place where 60% of our work is brake n clutch n id say every second falcon n commodore has run out in the rotors, major shudder/pulsation jus my 2cents worth from experience!
Cheer
Stedz

No-one said they didn't get runout
I said they rarely warped
Which is true
What your seeing on a regular basis Stedz is DTV
Which as you know on the Falcons is usually caused by the grease seal not being seated properly on the EA-EL models
And the bearings having angular float on the VS-VX Commodores due to the inner and outer cones of the sealed units being a mere 17mm apart and the tolerances between a new and worn bearing only being
NEW BEARING 0.106mm (0.0042�) MAXIMUM
USED BEARING 0.213 mm (0.0085�) MAXIMUM

And what shits me the most is people using rattleguns to do up wheelnuts
They should only be done by hand and prefferably with a torque wrench. Especially on cars fitted with alloy wheels

Gungy calipers and wrong spec pads can also result in DTV

Re warped discs
This is the best article I have seen on the matter http://www.stoptech....brakedisk.shtml

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#20 _CHOPPER_

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Posted 10 November 2006 - 04:44 PM

We stopped using rattle guns for final tightening at least 5 years ago. Yes, we use them to undo nuts and to nip them up, but the final tighten has always been by hand or torque wrench. More places are doing it these days.

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#21 _73LJWhiteSL_

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Posted 10 November 2006 - 04:53 PM

Also as Neil has pointed out You do not have KP rotors Steve.

I never claimed to have KP rotors mate, i if you double check the posts above, you see some people suggested i have KP rotors.

Hi guy's

Could it be the shocks????????????

cheers Keith

I'm running Koni Adjustable shockers which were only installed a few years ago, so i should hope its not shocks.

rack or tyre pressure?

Steering rack was replaced only a year or two ago. I always run 36psi all round, and i haven't changed the tyre preasure since the shuddering started.

And what shits me the most is people using rattleguns to do up wheelnuts

HELL YEAH! :furious:

All four of my Sprintmasters have big divets down the sides from rattle guns, and all the shinny coating on my wheel nuts is chipped and falling off. I tell places that replace my tyres not to use rattle guns.

Thanks for the link Neil, quite interesting reading....

"...Ideally, in order to avoid either putting up with squealing brakes that will not stop the car well around town or with pad fade on the track or coming down the mountain at speed, we should change pads before indulging in vigorous automotive exercise. No one does..."

Steve

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#22 TerrA LX

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Posted 10 November 2006 - 07:27 PM

73LJWhiteSL you say this was replaced 1 year ago and that was replaced 3 year ago etc etc but have you actually checked these things?
you cannot rule anything out till you have actually checked it for wear.

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#23 _Oldn64_

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Posted 10 November 2006 - 08:12 PM

Also as Neil has pointed out You do not have KP rotors Steve.
I never claimed to have KP rotors mate, i if you double check the posts above, you see some people suggested i have KP rotors.

I did not state you had KP rotor nor did I infer that you stated you had KP rotors, but you where looking for colour temperature dots which are only on KP rotors hence my comment, ie dont look for them as you do nto have them, is that better instructions? remember I have worked bloody hard this week. I know you know how that feels after last night but tack on two other sites which had similar results.

"...Ideally, in order to avoid either putting up with squealing brakes that will not stop the car well around town or with pad fade on the track or coming down the mountain at speed, we should change pads before indulging in vigorous automotive exercise. No one does..."

Ummm, not strictly true. I always change my pads and shoes as well as my fluid before all events. I have encouraged many to do the same but they have not seen the need for it yet. AT the end of teh day the car could run like crap and not perform all day, but you can still have fun, running around without brakes, tends to destroy ones day quite quickly.

Cheers

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#24 _73LJWhiteSL_

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Posted 13 November 2006 - 03:32 PM

Ok well it hasn't appear to fix my problem anyways, it is less but still there.

I have had the discs machined, and replaced both front wheel bearings.

The wheel sometimes wobbles side to side slowly under brakes, but it doesn't seem to do it when just driving. It seems strange that it doesn't do it all the time. I';m guessing maybe suspension bushes or something?

Steve

Edited by 73LJWhiteSL, 13 November 2006 - 03:34 PM.

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#25 _CHOPPER_

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Posted 13 November 2006 - 07:16 PM

I would be checking the castor bar bushes and crush tubes. This is a common problem with XR - XF Foulcans, the only difference is the bars go to the front on the Foulcans and to the rear on the Torry. The brakes try to stop the wheels and the radius rods ( aka castor rods ) stop the rest of the car.