Vibrations at low speed

[Nightchaser]

Hi,

I just bought a fren's wheels(n tires). However, there are some vibrations at low speed. The vibrations are characterised by a wobbly feel of the car at low speed (10-20km/h), kinda like a bit bumpy, but not so obvious at cruising or high speeds. Can any gurus or car freaks provide some insight as to what I should do to remedy the situation?

 

I have gone for high speed balancing at Stamford and the wheels are also balanced.

 

Thanks,

[Mondeo]

At first, is the wheels are for your car (off-set & center bore?)? Have you did any off-wheel balancing and alignment b4 done the H/S balancing.

[Guyver]

Welcome to MCF!! Do have fun here!! Btw..... regarding your low rev vibration.... there's alot of possiblities.... u'll need to try one.. by one.....

[Nightchaser]

I guess I will have to live with it..... dun wish to spend money and time investigating all the possibilities.

 

only thing is the mileage has dropped by 30km at the 1/2 tank mark... my suspicion is that the roll-off resistance has increased...

[Sparetyre]

Maybe high speed balancing is for high speed stability.

 

Since the vibration is at low speed, maybe need to go for low-speed balancing.

 

LOL

 

PS: Please do not flame me. Just fo fun only.

[Nightchaser]

Went to Stamford.... tires are fine... but the mechanic says my suspension needs replacing? how often do you guys replace the shocks? do u replace the springs at the same time?

 

my car is 4 years old and hitting 120,000km soon.....

[Hitman]

What car do you drive ??

 

Do you often carry heavy loads ??

[Sky8807]

Hi,

 

Not all wheels that fit on your car are sure correct. There are tolerences and off-set value to consider. If all else are according to specifications, then you can consider other things.

 

Suspension that are worn not necessary cause vibration but may cause uneven wear on the tyres. Spring that are bad most probably lower you car as compared to other of the same make and model.

 

Incorrect tyre pressure will also affect driving at slow speed, like over inflation. Poor wheel alignment is also a factor, since the car is 4 years old and don't know when was the last wheel alignment carried out.

 

A set of new tyres or wheel also need to run in before everything works fine.

How did the mechanic know that the tyres are fine, did he remove the wheel and check for balance or did a high speed balancing in front of you.

 

A simple wheel balance is sufficient if everything in the suspension is alright. No need to spent money for more expensive high speed balancing. If you are driving high speed car and does a lot of fierce driving and subject your car to rally type of torture then maybe the additional cost is justified, otherwise it is $ wasted.

 

My opinion.

[Nightchaser]

Hi, I know what you mean. In fact, technically I know what is there to know for wheels, like having hub-centric wheels, spacers, spignot rings and all that. The rims I fitted in fact came from an identical car. Its not hub centric but the rings are in place.

 

All the balancing and stuff were done in FRONT of me, literally.

In fact, I went back after a week again to ask him to check for flat spots and budges in the tires, but they were certified ok . As for pressure, it was the first thing that came to my mind.

 

btw, high speed balacing is not expensive, just 20 bucks and thereabouts. You need to do it if you are changing rims sometimes(as I have learnt). There are actually two types of balancing, off wheel and on wheel(high speed). off wheel I think checks for whether the wheel and rubber are evenly weighted.On wheel balancing as the term implies corrects for some abnormality when the balanced wheels are rotating on the car.

 

What do u think of changing just the front shocks? I think the back is ok, but the fronts are oscillating a bit. sigh... I also dun want to waste money man.....

[Sky8807]

Changing the front shocks of identical type and model of existing one alone should be alright I think. But if the shock is of different make then a set of four is a better option.

 

IMO the contributing factor is still the tyres and balancing. Previous to the tyre change, if there are no such vibration felt and changing the wheel/tyre the problem prop up then it less likely to be the shocks.

[Sparetyre]

Why not go to some reputable workshops and get a second opinion?