Help with steering vibration
Discussion
Hoping someone might have some experience with having resolved a similar issue. It's a mk2 Tuscan, with upgraded discs (330mm front) and Ferodo DS2500 pads, both around 500miles old, with no serious use or trackdays etc.
Recently been having an issue with a wobble through the steering wheel during medium braking. Light or hard braking it doesn't show up so much, but under medium braking especially above 30mph, the steering wheel visually wobbles left to right. Car still brakes in a straight line, and you cannot feel any vibration through the pedal.
The usual culprit would be warped discs, or something wrong with the discs/pads however the discs are about 500miles old, and been checked with a DTI. Being the upgraded discs then i doubted they had warped.
So... what also needs to be checked? All bushes look good, so we're thinking maybe the track rod ends, or maybe even the rack itself.. would this vibration be a symptom of the rack failing?
Recently been having an issue with a wobble through the steering wheel during medium braking. Light or hard braking it doesn't show up so much, but under medium braking especially above 30mph, the steering wheel visually wobbles left to right. Car still brakes in a straight line, and you cannot feel any vibration through the pedal.
The usual culprit would be warped discs, or something wrong with the discs/pads however the discs are about 500miles old, and been checked with a DTI. Being the upgraded discs then i doubted they had warped.
So... what also needs to be checked? All bushes look good, so we're thinking maybe the track rod ends, or maybe even the rack itself.. would this vibration be a symptom of the rack failing?
Thanks both but the discs were bedded in properly (pretty much exactly as you've just confirmed Dave 
)
And also been checked with a dti and they're not warped or have any high spots from what we can see. I'd also expect some vibration to be felt through the pedal if they are bad enough to cause the steering wheel wobble?
Is there any downside to maybe cleaning the discs and pads up and then doing the bedding in process again from scratch?
We're going to stick the car over the pit again and check all the steering linkages to be sure but I guess the only way to fully rule out the discs is to try another pair?! If that fixes it then hopefully I can get another set from the supplier as it shouldn't be happening after 500 normal miles
Or maybe I need to just send them back to be checked by the supplier on a lathe or something.
)And also been checked with a dti and they're not warped or have any high spots from what we can see. I'd also expect some vibration to be felt through the pedal if they are bad enough to cause the steering wheel wobble?
Is there any downside to maybe cleaning the discs and pads up and then doing the bedding in process again from scratch?
We're going to stick the car over the pit again and check all the steering linkages to be sure but I guess the only way to fully rule out the discs is to try another pair?! If that fixes it then hopefully I can get another set from the supplier as it shouldn't be happening after 500 normal miles
Or maybe I need to just send them back to be checked by the supplier on a lathe or something.
Edited by MrChips on Monday 31st October 17:56
Right, this one is still ongoing.. found some play in the rack, and in the UJ, so have had the rack referred and replaced the steering UJ. Also changed the drag link bushes.... and our survey says... the vibration is still there.
There's no vibration at all when coasting or accelerating, only when braking.
To try to avoid just replacing the whole front end bushes.. I guess the next step just for my sanity is to swap the discs and pads off a known good car just to be 100% sure it's not the discs themselves. They're the 330mm upgrade kit from Dom although i understand that they're not selling them anymore. If it is the discs, then what would be the general consensus on how to deal with it? they've done 2k miles, no track work at all.
There's no vibration at all when coasting or accelerating, only when braking.
To try to avoid just replacing the whole front end bushes.. I guess the next step just for my sanity is to swap the discs and pads off a known good car just to be 100% sure it's not the discs themselves. They're the 330mm upgrade kit from Dom although i understand that they're not selling them anymore. If it is the discs, then what would be the general consensus on how to deal with it? they've done 2k miles, no track work at all.
ClassiChimi said:
How are the calipers fixed to the hubs, any spacers/washers used at all?
I have the Brembo 324 mm brake upgrade on my Chim,
I had similar brake judder
Id fitted the calipers and new discs and pads, done loads of emergency stops to bed them in then went on a track day, only on track when braking very aggressively from high speed did I discover judder from the N/s front brake, steering wheel going left to right and almost out of control.
I'd used two 0.5 mm shims to centre the caliper to the disk,
I removed one of the shims,, makes very little difference as the pistons soon take up the slack
Added some 3M tape on the rear of the pads and started again.
I'd done at least 500 miles by now, I'd noticed that the outside pad wasn't pressing against the disc on the outside edge 15mm or so very effectively, after 1000 miles they had eventually worn and added material to the outside edge of disc.
It took a long time to get the discs to bed in but now they do not judder.
Fantastic brakes.
Do you get any brake squeal when there hot and coming to a gentle stop?
Some pictures of the brakes might be of help.
If it's only happening on one side I'd defo say it's the brakes, check for suspension/wheel bearing/track rod end movement while your at it.
Goodluck
ETA 2000 miles, ok, hmmm.
As mentioned above, I've noticed on a number of occasions the pads have left visible marks where I've come to a stop with warm brakes, once these big brakes bed in they should be deploying plenty of material into the discs as they operate so can we see a pic of the discs, I notice with my Chim that normal driving conditions the brakes are so effective I barely touch them and they still stop the car effectively, if I never did brake tests the pads would have hardly worn even with thousands of miles into them,
Check everything is tight and do the brake tests again, I tend to run my left foot on the pedal for a few swpeconds at a time, get them hot then do the tests, these big brakes are under employed in reality so you've got to get them really working on our cars to bed them in.
,
Thanks for the reply I have the Brembo 324 mm brake upgrade on my Chim,
I had similar brake judder
Id fitted the calipers and new discs and pads, done loads of emergency stops to bed them in then went on a track day, only on track when braking very aggressively from high speed did I discover judder from the N/s front brake, steering wheel going left to right and almost out of control.
I'd used two 0.5 mm shims to centre the caliper to the disk,
I removed one of the shims,, makes very little difference as the pistons soon take up the slack
Added some 3M tape on the rear of the pads and started again.
I'd done at least 500 miles by now, I'd noticed that the outside pad wasn't pressing against the disc on the outside edge 15mm or so very effectively, after 1000 miles they had eventually worn and added material to the outside edge of disc.
It took a long time to get the discs to bed in but now they do not judder.
Fantastic brakes.
Do you get any brake squeal when there hot and coming to a gentle stop?
Some pictures of the brakes might be of help.
If it's only happening on one side I'd defo say it's the brakes, check for suspension/wheel bearing/track rod end movement while your at it.
Goodluck
ETA 2000 miles, ok, hmmm.
As mentioned above, I've noticed on a number of occasions the pads have left visible marks where I've come to a stop with warm brakes, once these big brakes bed in they should be deploying plenty of material into the discs as they operate so can we see a pic of the discs, I notice with my Chim that normal driving conditions the brakes are so effective I barely touch them and they still stop the car effectively, if I never did brake tests the pads would have hardly worn even with thousands of miles into them,
Check everything is tight and do the brake tests again, I tend to run my left foot on the pedal for a few swpeconds at a time, get them hot then do the tests, these big brakes are under employed in reality so you've got to get them really working on our cars to bed them in.
,
Edited by ClassiChimi on Wednesday 14th December 21:43
The callipers have the slightly larger spacers needed to accommodate the discs yes. These were skimmed when fitting as they were originally a bit too big.
Here are the pads when i first took them out. I did notice that it looked like the inside pad on the drivers side wasn't cleaning the disc quite as much when just moving the car in and out of the garage.
The callipers have since been off and been checked over and are all moving freely so maybe it could be something relating to the spacers. The effect i'm seeing is exactly as you described, with the steering wheel visibly wobbling left to right under braking. I can take my hands off the wheel, and the car still brakes in a straight line though.
The car is with a well known garage who i trust fully, but they obviously don't want to simply throw parts at the car so are trying to help me keep the bill down! I was gutted when they drove it after doing the rack and the UJ that it was still there but at the end of the day this is one niggle that i can't ignore nor fix myself.
All bushes etc have been checked.. i did wonder about the wheel bearing, but that would show other symptoms when driving normally i would think? same for any wheel imbalance? (only done 1k since this was done last as well)
I gave my old discs to a PHer but they've been kept outside, plus these were new discs and pads at the same time so would be bedded in together. I think the only way of testing the brakes is going to be finding someone willing to swap theirs onto mine to test for a couple of miles. There are a couple of people locally within our Berkshire region who may help but i can understand it's a tall ask!
QBee said:
Have you still got your original Tuscan disks and pads?
If you do, perhaps that would be the best test to try?
Perhaps controversially, in the absence of track days and track day speeds, i wonder whether you really needed the big brake upgrade anyway?
Sadly not an option to refit the originals, and i do understand the point about needing the bigger brakes, but the cost difference wasn't huge (the old ones needed changing really anyway) , plus i have taken it on track in the past.. just not since fitting these discs.If you do, perhaps that would be the best test to try?
Perhaps controversially, in the absence of track days and track day speeds, i wonder whether you really needed the big brake upgrade anyway?
Edited by MrChips on Wednesday 14th December 22:54
Yep, it's definitely a weird one.. Trouble is.. brakes have been fine for 2k miles.. this behaviour came on fairly quickly.. over the course of around 40miles. The pads are Ferodo ds2500 which i've had before, so not overly track focused, but i do drive reasonably quickly on the road.
It's a good shout on the spacers, although the callipers have been off and on twice and the issue is still identical but i'll suggest they take a look at the spacers themselves.
This is rapidly becoming the 2nd most annoying issue i've had with the car.. although it'll take a lot to make to the number one spot above the phantom dashboard squeak (i've fixed it with earplugs)
It's a good shout on the spacers, although the callipers have been off and on twice and the issue is still identical but i'll suggest they take a look at the spacers themselves.
This is rapidly becoming the 2nd most annoying issue i've had with the car.. although it'll take a lot to make to the number one spot above the phantom dashboard squeak (i've fixed it with earplugs
)Just a quick update (or lack of) for this one. I'm bringing the car back home for a few weeks so i can take some pics.
In an ideal world i'd fine someone with some 322mm fronts and just swap over to check it is actually the brakes causing the issue, however having changed the entire steering system, and the car driving fine when on throttle then it looks the most likely.
At least it's winter so i'm not missing using the car.. just getting fed up with it but will keep going trying to diagnose
In an ideal world i'd fine someone with some 322mm fronts and just swap over to check it is actually the brakes causing the issue, however having changed the entire steering system, and the car driving fine when on throttle then it looks the most likely.
At least it's winter so i'm not missing using the car.. just getting fed up with it but will keep going trying to diagnose
m4tti said:
Maybe the brakes are fine.
Sounds rotational. Have you examined the wheel bearing assemblies closely.
Everything has been checked as much as can be (without replacing) by the garage yep. Sounds rotational. Have you examined the wheel bearing assemblies closely.
Edited by m4tti on Wednesday 28th December 13:31
I've had wheel bearing issues on a previous car and they showed symptoms during acceleration as well as braking. Last time i drove the Tuscan, it was silky smooth to drive unless on the brakes. Obviously it could be that the braking force is simply highlighting an issue elsewhere as the forces are obviously different to those under coasting/acceleration.
My logic says to exclude the brakes first before going to the next step as there's a decent size list of what it "could be" so it's just a matter of figuring out what's best to start with, hopefully without just emptying my pockets needlessly.
Should pick up the car tomorrow night so i'll take it for a spin to check the symptoms are exactly as they were a couple of months ago before it went it for repair.
Just to conclude it from my side... new discs solved the issue completely. I've sent the older ones back to see if anything can be found as they were straight on a dti machine. I can only guess really but maybe there was a lip on one/some of the grooves. I'd definitely be interested to know but the seller dealt with the exchange without issue.
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