Lateral run-out.. Causes and effects?

Level 5 User Joined: 11 Apr 2006 Posts: 122

Hey, right the situation is this:

When i'm going roughly 50-60 I get a vibration through the car, i'm pretty sure that's the wheel balance but when I brake at that speed the vibrations get more violent.

The thing is though if I brake at say 80-90 It doesn't vibrate but I can feel a light pulse through the pedal. Same as if I brake <40 Just feels normal BUT if I'm on a slope and stationary and I let the brakes off slowly the car feels like it's stopping more at one point like it rolls then it stops a bit then rolls but it's hardly noticable at all but it's annoying me because I know it's there and i'm wondering if it's connected to the vibrations when braking at 50-60.

I'm wondering if I warped the disk that time it was binding against the caliper (I drove about 1mile like that)

What I do know:

My tracking is out
My wheels arn't balanced
My wheel nut's are torqued up right
The caliper bolts are torqued up right
The only thing behind the disc rotor was a thin layer of copper grease
I only have 1 contersunk screw holding the disc to the rotor on each side

Any help appreciated, thanks.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

get he wheels balanced and the trackign sorted.

Chances are if the disc isn't running true then the hub face is damaged or wasn't cleaned properly.

But you need to check it for run out

the disc securing screw isn't an issue, you don't need them at all.

Level 5 User Joined: 11 Apr 2006 Posts: 122

cheers for the reply.

hmm, the faces had some old copper slip on that was it I think. Do garages have something that can check the run-out factor?

Gona get the balance and track sorted, just waiting till I get new tyres, which is soon!

Something I have notice is when braking and cornering say at 50mph it won't vibrate as much as if it was in a straight line? Sounds like the nuts are loose don't it but they are ok, as are the bearings and balljoints.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

get a pencil, take the wheel off and hold it against the caliper, use a clamp. spin the disc, if it loses contact with the disc at a certain point then its not mounted flush.

Level 5 User Joined: 11 Apr 2006 Posts: 122

i'm sure it's out on one side, the side that was binding Sad

I remember when I was spinning it when I had the smaller washers on and the disc was touching very slighlty at a certain point. I'll do your test on the other side and if it's ok i'll assume the drivers side is warped. The discs are Â£40 so not bad but i really cba at this moment in time :p