Vibration at speed.

[touringlegend]

I seem to have a problem with vibration in my XR2 at the higher speeds it gets too.

The discs have been changed, the wheels were swapped and all 4 wheels were re-balanced and found to be fine.

Not sure at all what is causing this and I am sure it is affecting my performance as I would be more confident when during hard braking and changing gears the wheel didn't shake with me holding it one handed.

[Tim Falce]

Does the vibration come through the steering or car? Are the tyres OK? you may have a flat spot or bulge in the tread or damaged wheel. Check all the suspension components are tight and working properly but I would start with the tyres and wheels even to the point of trying another set to see if it cures it.

[Mike_Wooshy]

not a bottom ball joint is it ??? apart from falcemob said im not sure what else it could be if your wheels have been checked etc etc.

[Tim Falce]

Originally Posted by touringlegend

Not sure at all what is causing this and I am sure it is affecting my performance as I would be more confident when during hard braking and changing gears the wheel didn't shake with me holding it one handed.

Is it just during braking or all the time?

[AU N EGL]

alignment checked?

I use to get this high speed vibration when my bearings were about to go. I change bearings each winter and that vibration never returned.

[touringlegend]

It was suggested the tyres may be flat spotted but wouldn't that show up during balancing ?

It's all the time at high speed too, the actual dash shakes a bit..

[AU N EGL]

Originally Posted by touringlegend

It was suggested the tyres may be flat spotted but wouldn't that show up during balancing ?

It's all the time at high speed too, the actual dash shakes a bit..

Dash shaking? Not good.

I would also check any and all suppnesion connections. Ball joints, tie rod ends, control arm bolts.

It is more then just tires or wheel balancing.

Good Luck

[Tim Falce]

Originally Posted by touringlegend

It was suggested the tyres may be flat spotted but wouldn't that show up during balancing ?

It's all the time at high speed too, the actual dash shakes a bit..

No, they would just add weight to balance out any differential in the tyre but it still wont get rid of any flat or high spots.
Jack the car up and rotate each wheel while running your hand over the surface of the tread to feel for any bulges, flat spots will be more difficult to find.
Was it doing it at your first race last week?
Start with the simple stuff and try another set of wheels and tyres on it.

[ian.stewart]

Make a fixed pointer, Mag mount and a scriber works well, or even a DTI[clock gauge] and check for Runout on the wheel when on the car, could quite easily be a bent wheel or bent hub, Check the rears as well

[touringlegend]

I hope it isn't anything like ball joints - it's been checked and prepared by the team I get to run it.

The car is about 80 miles away from me now, but I'm going to see if I can get it out on track and the team guy can have a shot in it to see what he thinks.

I am buying a new set of tyres for next year, so maybe that will cure it. The car had sat for the best part of a year, not being raced at all.

[Tim Falce]

Check the wheel bearings

[AU N EGL]

Car sat for a year? on jackstands or its tires? If it sat on its tires, I would say the tires are shot and flat spotted do the cars weight.

IMO race cars should not sit on race tires, jack stands between events or OLD wheels and tires, but not the race tires.

[touringlegend]

When I viewed it, it was sitting on it's tyres.

It came with 8 wheels/tyres though so they have been swapped about a bit, but maybe a new set will solve it.

Maybe I should of maxed out the credit card last weekend and got new tyres! I just thought as it was my first race, and the last of the season there wasn't much point in going for new tyres.

[AU N EGL]

before you get new tires, I would check every bolt in each wheel well, suppension, ball joints, then bearings- everything.

[johnny yuma]

it would take a lot to make the dash shake.Balance problems seem to kick in about highway cruising speed -annoying-but then lessen as speed rises (other people tell me).Yours sounds like flat spot tyres or bent driveshaft.Chances are it didn't get a bent shaft sitting around so ....

If it is a balance thing,some workshops balance "on the car"which is better as other rotating components may be a tad out.

Finally if it is more pronounced under brakes it may be pad material unevenly deposited on the rotors AS WELL.This can be sanded off use garnet paper.

[trikesrule]

Assume the steering wheel is a clock. The centre of the shaking left to right at the rim edge will point the direction of where the problem is located in the car. This will help point the way.........trikes

[fredmol]

if the tires are ok and there is no mechanical issues, this problem can be a shimmy phenomena. How much caster angle are you using?

[THR]

unless its something little, its tyres,
esp if they a bit old, and not road tyres, its tyres.
at 100mph it dont take much to be a bit unbalanced!!!!!