MASSIVE understeer

[robkendall]

Is this a symptom of the suspension being knackered?
me and the missus recently swapped cars,so ive got the 480,whislt shes driving me t4.....i noticed today, going around a corner....not really that fast that the car decided to carry on in more or less a straight line!!
After apologising profusely to the driver of the car coming the other way for scaring the living shite out of him, i went up some lanes near us, and pushed the car around the corners, and found that i was having to really compensate on the corners....the car was drifting really badly out of the corners, which it never seemed to when we first got it.
the tyres are ok, so its not 'slippage', ive bounced the car and it seemed ok, but having read posts by other members, this is not the most reliable way of testing suspension.
what do i need to change on the suspension, as i would think just dampeners and springs, but are there torsion bars and such like?

any help appreciated.

cheers
rob

[rpruen]

Is this a symptom of the suspension being knackered?
me and the missus recently swapped cars,so ive got the 480,whislt shes driving me t4.....i noticed today, going around a corner....not really that fast that the car decided to carry on in more or less a straight line!!
After apologising profusely to the driver of the car coming the other way for scaring the living shite out of him, i went up some lanes near us, and pushed the car around the corners, and found that i was having to really compensate on the corners....the car was drifting really badly out of the corners, which it never seemed to when we first got it.
the tyres are ok, so its not 'slippage', ive bounced the car and it seemed ok, but having read posts by other members, this is not the most reliable way of testing suspension.
what do i need to change on the suspension, as i would think just dampeners and springs, but are there torsion bars and such like?

any help appreciated.

cheers
rob

The quickest to check is tyre pressure. I had this when someone decided to pump the tyres up to the maximum written on the sidewall (44psi as I recall).

Other than that, is it front, rear or both that are letting go?

It could be dampers. Springs I don't see being a problem, unless you fill the car with bricks on a regular basis. It's worth checking the free length if the car looks to have sagged.

Odd because the 480 seems to be very good at cornering.

Richard

[robkendall]

hi rich....
tyre pressue is 32 psi all round.....good tread on tyres etc.
its been like that since we got it,so thats not changed,even if the pressures not the recommended setting, itdidnt cause this before

I think theback end looks a little lower than it did, but my gf says not, so that could be me!
the whole car seems to slide side ways,but starts at the back....if i 'twitch' the wheel, it will pull back in.
also,i ve noticed that when cornering, if i go over a 'pothole' or grate or any other protruding thing, the car seems to jump sideways.
its a little disconcerting,because like you said...the 480 normally corners faster and more smoothly than my t4.
might go to kwik fit and get it checked....they do a free check i believe?
rgrds
rob

[rpruen]

the whole car seems to slide side ways,but starts at the back....if i 'twitch' the wheel, it will pull back in.
also,i ve noticed that when cornering, if i go over a 'pothole' or grate or any other protruding thing, the car seems to jump sideways.
its a little disconcerting,because like you said...the 480 normally corners faster and more smoothly than my t4.
might go to kwik fit and get it checked....they do a free check i believe?
rgrds
rob

Hi Rob,

If it's starting at the rear, then I'd suspect the rear dampers, and or springs. Particularly as the car jogs sideways on bumps.

The other thing to try would be to take the car out and drive in a zigzag, you should be able to get some idea if anything is loose, or if one corner dips more than the rest. You should also be able to hear / feel any loose bushes.

Kwik fit may do a free check, but I have no idea how good it will be. I have always found that they try to sell you stuff you don't need. A few times they have tried to get me to buy new discs for the brakes, when they are fine (thickness well within spec, and no other problems), it's funny how they can see they are worn out without measuring them

Hope you have a better experience with Kwik fit.

Richard

[gerrsvolvo]

If a firm like kwik fit does a free check, do not trust them. They want to sell.

On your problem
Dis you check for tyrepessure (stupid me you wrote 32 psi all a round)
Did you check the profile.
Did you change your tyres or are the tyres getting old.
What is he make of the tyres.
Even tyres get old and less good in handling.

Bear in mind a good car like the 480 needs good tyres.

But also suspect the shockabsorbers.
Good or bad shckabsorbers are two different worlds in driving.
I myself only trust the Koni´s.
Good luck
suc6
Gerrsvolvo

[robkendall]

the tyres are in general good state.
they are pirellis (p6somethings), and the reciepts we got with the car say they are about 18 months old.
I even thought i may have had oil or something on them, making them slippy, but this is also not the case.
am scratching head at moment....will at least try kwik fit, am sorry to hear that people have had bad turns with them....any other companies that do free tests???

rgrds
rob

[gerrsvolvo]

Hi Rob
I still think that you should remember that the tests they make are for selling tyres or what else they want to sel.

The tyres you mention are not to old if trhey are 18 months old on the car. But what does the DOT number say about production date?
And Pirelli should be great on the car unless it are Pirellis from the Dutch Kwik Fit. Autoweek once published an article where they revealed that the Pirellis Kwikfit sells are most probably specially made for Vokswagen first use. But that the Dutch importer always removed these tyres from the new cars in order to mount the Continental tyres they are also importer from. And sells the Pirellis as a batch to Kwik Fit.
And as these tyres are specially made for first installation on the car the construction is different from the tyres sold for the replacement market although the profile is the same.

But first take a good look at the shockabsorders. How old are they.
And if the are not the originals or Bilstein or Sachs or Koni as replacement then have a good check and suspect tehse shockabsorders together with the rubber mountings.
Good luck
Gerrsvolvo

[johnd]

Isn't the front pressure meant to be 30psi for a start??

John

[dbsvolvos]

if your motor has drastically changed all of a sudden try anti roll bar links - they can get rusty and break or wear out , therefore quite a difference in roll resistance from front to rear . it could also be those stupid wishbone bushes - if they are knackered your geometry wont be right , something to check .

[robkendall]

@ johnd....even though its not the 'recommended' pressure, its not been a problem until now....would a couple of psi make that much difference anyway?

@ dave(dbs) will have a look at the roll bars....someone else suggested this also, as whatvere has happened has happened suddenly.

doesnt help that me missus has been using the car as a truck!!
rgrds
rob

[volvofox]

its not the damopers. the tyres are easy to check. Like dbs i think at realinement of the wheels, caused by whear of bushings or maybe an acident. (woman, tell me about it)
I remember my car doing as odd as you descripe after an acident (that bent my subframe in this case). Any of the likes of it are inmanginable.

go to a good tyre garage(not kwikfit, they haven't got the right bench for it, as its expensive)

Ps, if a car wants to run straight in a corner thats oversteer ? (might be wrong, school days are way gone)

don't believe anyone at first glance selling dampers or tyres. check wheel allinement.

[robkendall]

i always thought that it was understeer (hence thread name)
as in not steering enough??
wouldnt oversteer be too much, under not enough?

how is wheel alignment checked?
(is this like checking the tracking)
rgrds
rob

[volvofox]

long time ago. as said i might be wrong.

they set your car on a special "bridge" the front wheels on "turnable tables" they hang an electronic device on each front wheel, mostly with a laser. and shine a light on the front wall equipped with gauges, electronics, etc. this is about how it looks. some older ones work with mirrors.

I would not trust quick fit on this job. go to a good tyre dealer, don't get talked around with bullshit.

maybe the missus hit an obstacle quit hard one day with one wheel, and forget to tell you.

I hope its just this.

Nightmare senario would be a wrecked differential, dito gearbox. no differential means the car takes a corner like a playtoy car, with both wheels slipping the other side (hence the steer effect)

[chris1roll]

To do that wouldn't the diff have to be locked? (I discovered the tractor wont turn at all on road with the diff lock on )
I can see where your coming from, but wouldn't a diff failure cause the wheels to not turn at all?? (I'm not sure on this one)

[bbf]

broken diff could couse the 'lock' effect. if the diff's planets get stuck, this is practicaly locking the diff. the planets are spinning without bearings - ectualy they don't spin much, only when wheels are not straight or one is slipping.

[rpruen]

To do that wouldn't the diff have to be locked? (I discovered the tractor wont turn at all on road with the diff lock on )
I can see where your coming from, but wouldn't a diff failure cause the wheels to not turn at all?? (I'm not sure on this one)

One of the common failures of a diff is for the gears to become locked, usualy something has to drop into the gears, or if you wheelspin a lot then they can sieze. Both will lock the front wheels together, to turn one of the tyres has to break it's grip on the road.

The tractor has massivley more grip on the rear, and the front wheels can't create enough force to break the grip on the road, this doesn't happen on most cars, as the front wheels are more loaded than the rear. Of course the 480 is front wheel drive, so that doesn't exactly apply here.

Richard

[chris1roll]

Ahh. I get you, ok.

[volvofox]

To do that wouldn't the diff have to be locked? (I discovered the tractor wont turn at all on road with the diff lock on )
I can see where your coming from, but wouldn't a diff failure cause the wheels to not turn at all?? (I'm not sure on this one)

One of the common failures of a diff is for the gears to become locked, usualy something has to drop into the gears, or if you wheelspin a lot then they can sieze. Both will lock the front wheels together, to turn one of the tyres has to break it's grip on the road.

The tractor has massivley more grip on the rear, and the front wheels can't create enough force to break the grip on the road, this doesn't happen on most cars, as the front wheels are more loaded than the rear. Of course the 480 is front wheel drive, so that doesn't exactly apply here.

Richard

I am sorry, this is to black and white (to be or not to be---silly)
Its still a nightmare senario, (so don't have to be true) a jammed diff on the fwd 480 can get steering problems... in a greyscale.

(eat this.... what if a 4wd tractors front wheel differential jamms hehehe)


step 1. just get the car realined at a good firm.

step 2, look further, maybe worry about limited , or no slip in the differential.

[robkendall]

ok...ok...
i know this is the in depth tech forum, but this is all getting a bit beyond me!!!!
give me a mainframe, or any computer system, and i will make it sing, but as far as car mechanics go, im a real novice (petrol in that end, keys in that end...car goes vroom!)
can anyone suggest a decent mainstream outlet (other than kwik fit!) who would be able to check out my car for me?
the other restriction is that im working permanent night shifts at the moment, so im really limited to what I can do, as i sleep a lot during the day.

rgrds
rob

[rpruen]

I am sorry, this is to black and white (to be or not to be---silly)
Its still a nightmare senario, (so don't have to be true) a jammed diff on the fwd 480 can get steering problems... in a greyscale.

(eat this.... what if a 4wd tractors front wheel differential jamms hehehe)


step 1. just get the car realined at a good firm.

step 2, look further, maybe worry about limited , or no slip in the differential.

I only mean the tractor part doesn't apply. Having the diff lock up is still bad news on a front wheel drive.

Its easy to check the diff. Just jack up one front wheel, and turn it. If it turns without dificulty the diff is ok.

The 4wd tractor will turn if the front diff is locked, just not very well. The steering wheel might try to break both your arms though.

Richard.