Vibration under braking 60-40 only

[Jfox]

Hi guys,

I have a bit of a weird issue here.

I recently had new discs and pads all round on my 2008 Cupra.

Had a new wheel bearing as well as it was pretty much nackered.

I also found one of my rear calipers pistons would not go back in so had a new one of those as well. nice general maintenance.

Anyway, since getting these done when im braking from around 70/80 i get a very bad vibration (its hard to tell where) when going from 60-40mph...after that it stops and above i dont get it either.....

I'm really not sure what it could be. Initially i thought, ok a simple airlock in one of the calipers but surely the fact that it only happens between 40-60mph would rule that out?

Also, ive had this for a while now, my last set of tires only lasted 6-7k miles (hankooks) with seriously inside edge wear eventually causing a puncture...

I do have quite a nasty steer wheel wobble at 60+ as well... I am thinking its all related.

had a quick google and a few things have popped up.

1) Alignment could be out - probably as i have clipped a curb outside my mates house due to some stupid idiot not stopping and almost hitting me.
2) same reason as the above but i bent something, wishbone, drive shaft, drop link???
3) nackered CV joint (but dont really have the usual symptoms)
4) ball joint worn - On a honda forums i did read that someone had similar issues to me and it turned out his ball joints were pretty much nonexistent with wear.

What do you think? Any advice?

I am going to ask the mechanic who fitted my brakes for me if he has any ideas and i guess its a good start to go get the wheels alligned and balanced and generally have the garage look to see if there is any play, worn bushes.

Any help would be very appreciated!!

Cheers

 

[mike0105]

I think your on to the right track with 4 wheel alignment and balancing, the latter will cause speed specific wobbles and it would fit with your recent incident.

That is very fast tyre wear and indicative of misalignment so that should have been sorted when you changed the tyres, or you should at least have been advised of the issue.

 

[Jfox]

Thanks mike.

Well the wheels were balanced with the new tyres, albeit cheap tyres (for the winter we havent had) but still i had a problem before this so i can rule out rubbish rubber.

I did some looking around and found a polo with similar issues. He spent a lot of cash changing different things from tie rod ends, tyres, wheels, discs etc... His discs had some throw as they were old. He changed them and the problem persisted.

I don't know whether it was fully resolved. Hopefully this will be something simple.

It may be to do with my new rear caliper.

I had the all the pads and discs changed while the rear passengers was left as the original until i got my caliper from Dave at Sere. This was changed a week later (so hardly any time) and during this i only traveled to work which is 20mile round trip.

I only seemed to notice the vibration when the new caliper and final disc had been replaced so again maybe an area to look at first.

As i have been living with the wobble at 50/60+ for a while i dont mind waiting a little longer. This vibration under braking is making me loose confidence and i would like to get that sorted first while alignment done later or at least with if its a possible solution.

Has anyone else had this issue?

 

[mty12345]

Have you checked the inner cv joints mate? They can cause vibrations at certain speeds when worn, be it braking or accelerating. They could be letting the gearbox end of the shaft wobble about slightly and it might only show at certain shaft speeds due to resonant frequencies etc. Hard to say, but that's what i would look at first.

That could also cause the vibration at 50/60 mph you mention too

 

[Jfox]

Cheers Matty,

I'm gonna get the mechanic to take a look at them tomorrow (hopefully he has some time). It really doesnt feel safe and i need to do some driving on the weekend.

so even if i can be assured its ok that will put my mind at ease until it gets fixed.

Maybe its a nackered rotor... i know they are new but its possible that it was warped a little.

CV joint might be a good shout considering the age and mileage, 67k 08.

I will definitely mention this. I want to enjoy driving my car again and not be p*ssed off every time i go above 40 haha - which is often!

 

[mty12345]

No worries mate, i hope you get it sorted soon. Both the inner and outer cv's have a hard life in powerful fwd cars.

 

[Jfox]

I just swapped my wheel over to the back and the wobble has stopped.

So I guess that means its a bent alloy. I have now got a slight rotational sound at low speed, again tho could be something related to the inside tyre wear.

I'm going to swap the other side over in a bit and see what that does.

I'm seeing the mechanic this afternoon and hopefully he can diagnose that weird vibration under braking.

I will keep you all informed.

Cheers for the help so far.

 

[Jfox]

Wont be getting the mechanic to take a look for me.. Just found out he is in hospital with a double hernia.

Il have to take it to a garage next week for a look. I have no play in my wheels at least.

 

[Jfox]

Swapped my wheels over on both sides.

Did the drivers side first (the alloy with the dink in it) and made it much better.

Then i swapped the other side and now the car feels a bit iffy on the road.

It doesnt feel as planted as before (still got a wobble so i guess its a fked alloy). It feels like its swaying a bit and steering isnt as sharp.

Il get the tracking and balancing done next weekend and may look into buying a new alloy perhaps.

I also need to get that vibration under braking sorted out!

 

[Jfox]

Hey guys, I think its a drive shaft that's nackered...

I swapped my wheels over and then back because of that damn alloy and I have a horrid rotational sound and I can feel it by my feet.

I will get it into the garage sometime this week hopefully and see what they say.

I'm looking forward to getting these issues sorted so I can spend money on what I want foe the car not what I have to haha