Steering pulls to right under power....

I have a Mk 2.5 1.8 - which is in good nick generally.  Recently had the geometry checked and adjusted and a rear nearside tyre changed ( as the outgoing was bald on the inside as a result of bad geometry…)

Only done a few miles since - but I notice the car is now pulling to the right very slightly under power - so that when you come off you then veer to left a little.  It definately didn’t do this before although clearly the suspension was out quite a bit … 

I took it back to the garage and they took a look and found the front castor was out on one side - after they adjusted this - it still appears to be doing the same thing.  I now feel disapointed  as having had it corrected it drives worse than it did with a bald tyre and wrong geometry !!

I am now suspecting that some of the bushes are worn?  despite checking these before we started the adjustments originally…   The car has done approx 68K. 

So some questions:

1/ What is the normal span for replacing bushes ?

(I assume they are std rubber on my car - not sure f they have ever been replaced as I only just recently got he car…)

2/ for sporting road use - are polybushes the best choice or are they too hard for road use?

 

3/ any thoughts on the pulling other than something worn in the bush dept ?

the new nearside rear  tyre is a Falken  the one on the other side is a Hankook?  would this affect it - Garage said they would match okay ?  Pressures all all within 0.5psi of each other …

 

Any advice appreciated… !

 

 

Brakes, tyre pressures, does she drive straight?

M-m

Basically drives stright under steady cruise conditions - when you accelerate hard it pulls very slightly to the right. Brakes pull up straight - I have new discs and calipers & pads on the front …

The car didn’t pull before I had it adjusted - but as I said it was quite away out on the raer nearside   qrtr of the tyre width was bald ( on the inside - where you can’t see easily) 

 

Tyres pressues are all balanced at 27psi

 

Had the exact problem on my first Mk2… nightmare, esp on wet roads!

Cured (completely) by firstly, a full 4-wheel alignment & geo setup, and then by fitting a new SET of Toyo T1R’s at the same time. FWIW, the tyres on the car were 4 different brands/ tread patterns, all different wear depths, and on rear axle, one directional & one non-directional. The oldest tyre 9 years old, worn, hard & lots of cracks. Geo setup revealed all parameters out, esp front AND rear toe-in…

IMHO, no substitute for matched tyres on an axle, pref on all four. THEN full 4-wheel geo setup.

 

Bill

Tackle the easy fixes, liked the tyres. Also consider that an alignment bolt is worn, and not holding.

thanks - I will have to get underneath and check the adjusters and the bushes for movement/wear… I can’t see tyre mix on the rear giving a steering issue personally… but as a last resort maybe…

It is a known issue on some that just running different brands on front to rear can produce issues with traction.

In some cases the different tread depths and designs could be the cause of the issue most MX5’s tend to be quite picky on having the same all around.

I think your car has an LSD, if it does and you have differently worn tyres on the rear than you will get exactly the symptoms that you have. Fit tyres of exactly the same size on the rear and that will solve it. If the fronts are a matching pair, try those on the back to prove it.
Alan

Well this is something worth making a conscious note of - I have checked all the suspension joints out with a crowbar ( substantial one at that ) no significant movement or play anywhere I could see.  Then with your comments in mind I pulled both wheels and put them side by side…

I don’t have a picture - but the difference we quite significant - the Hankook tyre has much squarer shoulders on it versus the Falken that was put on new a week or so ago.  The result is that the Hankook as more contact /tread area effectively…

So once I saw this - to cemment matters I swopped them and had another run out to see what the impact would be …

So Alan,  Ninja  Saz, Bill, & Mr Mazda Mender  your insights/suggestion were spot on…

I must admit I have run allsorts on my prior cars - not deliberately I might add - but just replaced them along the way with whatever I could get - never had anything like this before…

Having said that the tyres are most definately very different - had I spotted this before I think I woul dhave twigged it even without driving on them – 

Also I would add this is the first car I’ve had with an LSD… ( thats not an excuse though)

So in conclusion - tyre’s are best matched on the same axle at minimum…

Thanks to all - next Saturday hopefully have a new Hankook to fit on in place of the narrower Falken…

 

 

Lack of useful smilies… :thumbs up:

M-m

LaughingCool

 

thanks guys…