Wandering Tuscan

[Konrod]

I've been away for 6 weeks and got the Tuscan out this weekedn, to take for a long drive to see relatives. Just before we went away, I had two new rear tyres fitted (Dunlop Sport Maxx 255/35).

Whn we drove out and were driving along a section of road with mild ruts where trucks have been, the car was throwing itself a foor to left or right. I've had the Tuscan for 8 years so I know it can tramline (I have the 3mm spacers that improved it a lot), but this was pretty terrifying. We turned around and put it back in the garage and took the tintop.

When we got home is was going dark, I checked the tyre pressures which were 24 front and 26 rear (the usual settings) and the nuts which were tight, but not tight enough. I tried it again over the same road with the same result (it's a road I use regularly so I know how it should feel). The road was dry in both cases

It feels like the steering isn't connected to the front wheels correctly, but having had new tyres at the back my suspicion is the problem is there.

Before I go taking wheels off etc. has anyone else had a similar problem, and what resolved it?

Thx in advance

[Cats]

Mines a Mk 3 but changed the front tyres as they were 7 years old and done 27k miles. Stacks of tread left perhaps 4-5mm but was suffering with a bit of wandering on rutted surfaces.
Had the same issue on an Audi when the tyres were half worn but again on fat tyres.
New Goodyears has transformed the Tuscan back to what it should be and it's a pleasure to drive one handedly.
I keep my pressures at 22psi front and back.
Works for me.

[mk1fan]

There's an MOT test for the steering joints. Jack the front of the car up. Grab the wheel in the 3 and 9 position and check for play by rocking. Be careful as being too hard could knock the car off the jack.

Then grab the wheel at 6 and 9 and do the same test.

If there is 'knocking' movement then a joint has gone somewhere.

[s6boy]

Do you have the same Dunlops on both ends?
If everything is done up correctly and nothing has broken since you last drove the car it could be a mis-match with the tyres.

[Basil Brush]

New tyres can feel a bit dodgy until they've been through a few heat cycles.

[plasticman]

Are they runflats . I had a pair on the rear of my T350 and it was terrible .

[Konrod]

Thanks for all the replies.

They aren't run flats - I checked that out. The front tyres are half worn Pirelli P Zeros but I haven't been that happy with them so the plan was to put the Dunlops on and then change the fronts a bit later on. That might have to change.

I think I'll have to take the wheels off and have a look to make sure there is no mechanical damage - not hard just a pain and time consuming. I certainly don't want to drive it anywhere until I've done that at least. Assuming that is OK I'll try dropping the pressures a bit lower than usual and see what happens. If it is a heat cycle thing I don't see a way out - it is virtually uncontrollable on rutted roads and I'm worried it'll jump right and head on with another car, so it'll never get the cycles it needs.

[Basil Brush]

I'd be getting it put on 4 new matched tyres and take it from there. Given how sensitive they are to set up, differences in compound and side wall stiffness front to back aren't going to help matters.

[R TOY]

Had exactly the same thing a few years back, put new rears on just before heading to LeMans , Car was a nightmare to drive down , tramlining and wandering horribly.
By the time we came home it had improved considerably as the tyres bedded in.

Next time it needed tyres a full set was required and I expected to have the same issue but all was fine .

Best advice is book a track day to get the rears well and truly bedded in

[mk1fan]

mk1fan said:

There's an MOT test for the steering joints. Jack the front of the car up. Grab the wheel in the 3 and 9 position and check for play by rocking. Be careful as being too hard could knock the car off the jack.

Then grab the wheel at 6 and 9 and do the same test.

If there is 'knocking' movement then a joint has gone somewhere.

Do this before taking the wheels off.

Tamy had mis-matched tyres on her when she arrived in my life. Wandered all over the shop. Swapped to matching alround and there was an instant improvement (I also went 225/40/18 all round). Still pretty wandery though. Mat Smith tickled her geo settings and voila. Handles great.

[Malcster]

Worth getting the geo checked?

I went for this, and made a huge difference...

Front
-1.0 degrees camber (negative)
1.0mm (8minutes) toe in overall (divide by two for individual wheel toe)
Caster to max (~5 degrees) (adjusted via moving both shims to front (of car) on upper ball-joint, as opposed to one either side)

Rear:
-1.5 degrees camber (negative)
3.0mm (24minutes) toe in overall (divide by two for individual wheel toe)

[softtop]

Malcster said:

Worth getting the geo checked?

I went for this, and made a huge difference...

Front
-1.0 degrees camber (negative)
1.0mm (8minutes) toe in overall (divide by two for individual wheel toe)
Caster to max (~5 degrees) (adjusted via moving both shims to front (of car) on upper ball-joint, as opposed to one either side)

Rear:
-1.5 degrees camber (negative)
3.0mm (24minutes) toe in overall (divide by two for individual wheel toe)

Which one have you got?

[blueg33]

I mixed Dunlops with Toyo's on the Ginetta, it was a nightmare, put Dunlops or Toyos all round and it was fine. My Tuscan was always horrible for bump steer.

[Malcster]

softtop said:

Which one have you got?

Not sure what you mean?

Gaz Gold shocks, and Eagle F1 Assym 3s (225/40/R18 front, and 245/40/R18 rear)

[phazed]

The more tyres wear, the more they tramline.

Change the tyres around so that the new tyres are on the front and your problems will disappear.

[Speed 3]

phazed said:

The more tyres wear, the more they tramline.

Change the tyres around so that the new tyres are on the front and your problems will disappear.

Bit tricky with different sizes front to back

[phazed]

Speed 3 said:

phazed said:

The more tyres wear, the more they tramline.

Change the tyres around so that the new tyres are on the front and your problems will disappear.

Bit tricky with different sizes front to back

Damn, but that is your problem.

New tyres needed on the front.

[Konrod]

Hi All

Thought I would give an update where I am on this one. I've had the wheels off and had a look at the suspension/steering. No bent wishbones (which was my first thought) and the steering rack/track rods ends are all tightly in place. Did the MOT thing but there isn't any untoward play anywhere.

So, happy that the underpinnings were all as they should be, and I wasn't likley to die (or any more than usual, anyway) I took it out to a quiet bit of road and left several 11s on the tarmac to scrub off any remaining release material and get the new tyres up to a temperature. Actually, the new tyres were grippy and leaving 11s required me to lower my usual levels of mechanical sympathy.

Having got the tyres warmed, I burned 100 miles worth of 98 octance juice on fast A roads.

The outcome was that the wandering was much less violent/darty, but it is still there. So I've surrendered and having Dunlops fitted to the front on Weds.

Anyone want some 225/40/18 Pirellis PZeros, with about 6mm of tread? They're 18 months old and in good condition.

Cheers

Konrod

[Konrod]

New tyres fitted, problem solved.

Now a more serious question, why is it when you have tyres fitted a) you lose one of your logo dust caps (just one, mind) and b) whatever you tell them, they put 35 psi in it

[Speed 3]

Glad to hear, it’s easy to forget how sensitive light cars with sensitive handling are to the “black” arts. There can’t be many cars these days that your average tyre fitter meets needing 22psi.