Technical Wobble/Vibration Problem

[Ozzie1989]

Right guys I've got a problem, I can't get rid of a wobble/vibration on the Doblo that started (or at least I think it did) when I rotated my wheels round. I've had all the wheels balanced and checked 3 times, and it's still there.

All my wheels were out of balance by about 45-55grams which is quite a lot and may possibly have been like this for a while. No weights had fallen off (as they are the stick on type).

As soon as you reach 65-70mph there is a strong vibration/wobble which can be felt everywhere in the car and also heared, it sounds like a helicopter! It was continuous but driving up the motorway today it became intermittant, so I tried it decellerating, accellerating, coasting but it still remained so to me this ruled out any trasmission problems.

Anyone got any ideas? Would the tracking cause such a problem? The bearings don't appear to be the problem, I'm not getting that sort of continuous whine.

I'm lost as to what the problem could be and got a lot of driving to do over the next month (6x200mile trips) and wouldn't like anything to go wrong!

 

[RichDoblo120]

I had a similar problem on an old Peugeot but that turned out to be a bent wheel, after getting the wheels balanced and the tracking corrected .
I would start with the tracking then see how it goes.

 

[Ozzie1989]

Could the tracking really cause a wobble though?

Wouldn't want to spend £50 having the tracking done to find it no different

Going on Sunday so guess I haven't got much choice!

 

[RichDoblo120]

I've been told that the tracking can cause a wobble although a wobble at a certain speed is usually a balance problem.
Don't some garages check for free and only charge if it needs adjusting?
My local tyre place, Phillips Tyres, will check for free. Too far for you I spose but I think Kwikfit will too.

 

[AppleSei]

Are the nuts on your wheels tightened up and/or tightened correctly?

 

[Ozzie1989]

Well I suppose it's worth a try, I have a friend at a local Kwik-Fit so I know he'll check it for me but if it is out then it's £45 I think... And even then it may not solve the problem!

I've just gone out and jacked up each wheel to feel for any play in the bearings or spigot rings fitted to the alloys and found nothing, they all seemed pretty solid. I also spun the wheel to check for any noticeable wobble or deform in the tyre or wheel and it all looked good.

Who knows eh?

And Apple, the nuts are tourqed to 100nm as specified by Fiat... I always tourqe them and so did Kwik-Fit this morning when we finished playing about with the balancing. Come to think of it, they tightened them up first of all in a circular order, and then tightened them in opposites, surely the wobbly bolts would have taken this up but it might be worth me fitting them again to make sure they're sitting central on the hub. In saying that the spigot rings would do that?

 

[RichDoblo120]

If it started when you rotated your wheels I reckon it's got to be a wheel or tyre problem.
Are any of the tyres out of shape?
Try spinning the wheel and seeing if a tyre is mis-shaped. A mis-shapen tyre will still balance up ok but would cause a wobble.
Maybe even a wheel is distorted. It's unlikely with alloys but still possible.

 

[bobian81]

ozzie heres a tip for you before you spend any money, take your spare wheel, put it on one side at the front, drive it see if its any better, if not swop it to the other side, if it cures it you've got a dodgy tyre.
..... rob

 

[Ozzie1989]

Rob I would do that but my spare is malformed somewhat, wherever I put it on it pulls in that direction, had it balanced etc. as well but to no avail... it is literally just for emergencies... might get one of the good steels out later and try that.

Taken it to a garage this morning of an old school friend, and he balanced up all the wheels and did the tracking for £30... not bad eh! The wheels were way out of balance (don't know what Kwik-Fit did and the weights were in the wrong place too (ie. on the inside instead of near the outside of the wheel). He also balanced both the wheel and the tyre (2 different sets of weights).

He was shocked because when he took Kwik-Fit's weights off the balance was BETTER than with them on! Perhaps their machine was a bit dodgy as they have theirs calibrated every few days and had a log to prove it.

Tracking was only a little out on one side so didn't make much difference. On the initial test run things are looking good, 70 is just as smooth as 50 BUT as soon as you go over 77-78 the wobble returns and you can't loose it again until you drop below 60? Strange! It must be a tyre malformed, but why would I not have noticed it before I swapped them round?

Any ideas to the wobble that has a mind of it's own? It's as if it's a bit tipsy and when it looses it's balance it cannot regain it until it slows down again!

 

[RichDoblo120]

Sounds like a tank slapper on a m'bike!
They start off gently then get worse when you slow down.
I won't let kwikfit near my wheels after what you've said
As a last resort you could put all your steels back on and see if this cures it, then you know for sure it's a tyre or a wheel. Alot of work though

 

[Ozzie1989]

As a process of illumination I'm going to purchase a bearing kit tomorrow and do the bearings on the rear (cannot feel anything on the steering so it doesn't appear to be from the front).

Anyone tried to do them before? Shouldn't be too hard on the back I hope

 

[sludgeguts]

Tracking these days is done over the whole car (yesteryear it was just done across the front wheels) not only across the front but across the back and back to front.
I used to take my car to one particular garage that balanced the wheels in situ. They sat on a machine which they rolled up to the roadwheel (with the wheels off the ground). This method not only balanced the wheel but also showed problems in the driveshafts & other parts of the wheel area.

I also thought they would balance a wheel by tacking weights to either side of a rim. Tacking to one side only would encourage wobble as, at speed, the extra weight - albeit an ounce - is off centre of gravity.

One more thing. Garages never used to bother balancing road wheels if they were going on the back because the whole assembly is fixed solid (although I guess it could, over time, damage bearings or suchlike.
Rotating the wheels would show up this problem - especially if you put both rear wheels onto the fronts - two unbalanced wheels OMG.

 

[Ozzie1989]

I also thought they would balance a wheel by tacking weights to either side of a rim. Tacking to one side only would encourage wobble as, at speed, the extra weight - albeit an ounce - is off centre of gravity.

Yes, the second garage did this, one hammered onto the inside of the rim and stick on ones just on the outside of it before the spokes (so you can only see them if you look through the spokes).

I might try the steel wheels first, see if that solves the problem. But as you said, the rear wheels are effectively fixed in position, it seems as though the problem is coming from the rear as I cannot feel anything on the steering... so maybe the lack of balance all along on the rear wheels has caused problems in the bearings and this is why I'm having problems now the wheels ARE balanced!

I'll also give my local Fiat garage a ring first thing in the morning, see if they can suggest anything

It's just so strange and come at a bad time... the strangest thing is that it comes and goes as your driving along which is why something is telling me it can't be a malformed wheel or tyre, nor the balancing now it's been checked again! It must be something else

 

[T14086]

does it get better when you brake?

 

[RichDoblo120]

If it comes and goes as you're driving, that might be to do with variations in the camber in the road, which might suggest a problem with wheel alignment or steering. Could this be possible?

 

[Ozzie1989]

does it get better when you brake?

T I haven't really found that out because it happens quite bad when you hit 80 and braking from there slows you down too quick to notice if the brakes are killing the vibration or the reduction in speed.

I checked for the 'pulsing' on the pedal of the usual tell tale sign that the discs are warped but it's smooth as anything!

 

[Ozzie1989]

If it comes and goes as you're driving, that might be to do with variations in the camber in the road, which might suggest a problem with wheel alignment or steering. Could this be possible?

It could, but I can't feel any sort of wobble or vibration through the steering wheel, it's smooth. This is why it makes me think it's coming from the rear.

My local Fiat tech suggested this morning that it could be the rear anti-roll bar, as they replace loads of these (Re: Squeaky Rear Suspension)... but we weren't sure if this would cause a vibration or wobble.

 

[RichDoblo120]

It could, but I can't feel any sort of wobble or vibration through the steering wheel, it's smooth. This is why it makes me think it's coming from the rear.

My local Fiat tech suggested this morning that it could be the rear anti-roll bar, as they replace loads of these (Re: Squeaky Rear Suspension)... but we weren't sure if this would cause a vibration or wobble.

Sounds like you're getting closer to finding the cause
LUKHYGO

 

[Ozzie1989]

Pffft a chance would be a fine thing!

I'm heading off on a 200mile trip Sunday and working all day tomorrow so the chance of finding it before I go is slim

Just have to hope driving it doesn't cause any damage or a wheel doesn't fall off or something

 

[captain_swing]

Ozzie

Just asking the obvious, but they have tightened the wheel nuts properly haven't they?

Sometimes it's the simplest things.