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MG MGF Technical - Tyres and unstable handling

Hi folks, just put on new Goodyear Eagle F1 GSD3's on the rear of my MG TF 120 (2004) and the car now drives in a very unstable and dangerous manner...a bit like being buffetted in a storm. Alignment/ balance/ pressure are all good. Front tyres are also F1's in half to 3/4 tread. Any ideas appreciated. Lawry
L Scandar

I'm sorry to tell but this looks like the classical problem, Did anyone advice you to use de GSD3'S?

There was a MG-Rover message out, long ago for the MGF: Not to use GDS3's in combination with GDS2's. This affects the handling of the car in a very unpleasant way.

I'm not informed well regarding this effect on the TF, but could well be the same problem.
Kasper

Lawry,

It'll take a few hundred miles for the mould release agent to wear off. Once this has scrubbed off you'll notice a big difference. I've had this before with new rear tyres and it feels as if the car is being steered from the rear. Mine was so bad that I thought the tyre fitter had broken something and I had the car checked over - nothing wrong. Eventually everything was back to normal.

As Kasper says GSD3s are not recommended and should not be mixed with GS2s, but I would think that they will be OK for normal driving. Many people have run GS3s on all four corners and say that the handling is fine.
David Clelland

Thanksfolks...I'll drive a few more 100 kms and report the effect. I'll also chat to the tyre dealer...he stated that the D3's were the D2 replacemtn (not available?) Regardless...I'll have to sort this out, as the drive is far too erratic and unstable. Not really wanting to put out money right now for new D3 fronts, as they have good life left in them, but if I have to for safety...well...no argument there I guss!

Lawry
L Scandar

Lawry,

A few years ago I replaced my rear Toyo tyres with exactly the same type and size that came off and as I said above the car handled as if something had broken (it wasn't too bad in the corners but felt as if it was rear wheel steering on the straight). I then did an 800 mile trip and the handling still wasn't back to normal. The week after I got back I was due to do a track night at our local racing circuit and I was in two minds whether to do it or not. I eventually decided to do a few easy laps and as the night went on it just got better and better until all was back to normal. So it actually took me nearly 1000 miles and about 10 laps of a racing circuit before the car felt as if the handling was back to normal - so give it time.
David Clelland

David...maybe I need to book a few hours at our local Driver Training Centre....a few hours of lapping around their circuit at speed would be therapeutic for many reasons!!!! I'll certainly report back after more kms! Thinking of taking a few long open road drivves this weekend!!
L Scandar

Hi there, I seem to have a similaar problem to that you are describing i.e. rear end wander. However mine has just occurred on my last outing a 250 mile day out. On our way home the car started to wander under power. I checked tyre pressures and tried to feel for bearing wear, pressures OK and all seemed OK. I have been out again today and noticed it again spasmodically. I have Toyo tyres fitted 5000 miles ago and no previous experience of the problem. Any further ideas on this subject would be welcome as I have lost my confidence in the handling which has been excellent up to now.
R S J Dunn

If it has just come on after your day out then something is amiss, the rear bearings can fail but the hub makes it hard to tell - take the wheels off and check the hub nut.

As for tyres, I had the same when I replaced the rear Contis on my TF135 - it felt horrid for a good 1000miles.



Has anyone swapped the Contis for a full set of F1 GSD3s on a TF135 on standard wheels? Just curious as I will need to do all 4 at some stage.
Tony

This is formerly declared wierd: my car's got exactly the same problem! It's been used predominantly been used on short trips for the last 8 months, as my recent jobs would involve 100 mile round trips (no thank you - I'll let the train take the strain). But drove to work the other weekend and it felt that the rear wheels are steering themselves (passive rear steer). The sensation is like having a side-wind blowing the rear off course.

Not had chance to investigate much, but the inner edge of the nearside rear tyre has more wear than the outer edge - so looks like it's going to be the bearing (irritating, it's only 2 or 3 years old) or the track rod ends...
Rob Bell

Hi folks...have had discussion with a tech expert from Goodyear...he agreed that mixing GSD3's with GSD2's is not good! Suggestions so far are...run them a little longer and see....replace thefront's with GSD3's to have matching 4, consider a com;lete alternative...and finally...his research has uncvered an old (2004) MG tech Bulletin that says to run tyres at 29 psi. I've beenrunning my tyres at the 36 - 40 psi mark for years, but will try this for a day or two and report back.

What pressures are others here running theirs at? (Mine is the 2004 MG TF 120)

Cheers,

Lawry
ps. Rob...bit of bad luck if it's bearings after such a short time..my previous tyres wore on the inner edge, and an alignment sorted that ot.
L Scandar

This thread was discussed between 26/06/2009 and 01/07/2009

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