newbie help

[white-zed]

hi all i have just bought a '98 c180 auto (w202) and i must say the car has been great handles well etc, well at least it did, i had some new tyres fitted last weekend as the rear ones were worn right down (i had one avon and one pirelli on the rear) so i kept the pirelli as it had good tread and used the spare and the one rear wheel to have the new tyres on, got them balanced and fitted used the car fri night towing a trailer only to find the rear end was very twitchy, it would suddenly pull to the right or left at random intervals and when overtaking and pulling back in the back just felt like it lunged over.
so i checked the tyre pressures they were below spec so i inflated them to correct pressure used it to day up the m50 no probs felt fine, coming back had the back end twitching again at one point i thought the body was not connected to the wheels, this twitching only happens between 70 + 80 mph (65mph with trailer on), happens at totally random intervals and the only thing i have changed is the tyres on the rear? any ideas what the problem could be? many thanks kev (p.s there were no crosswinds when i've had these problems)

 

[Ron Palfrey]

The way I read your post you now have one new tyre on your spare wheel, a used Pirelli on a rear wheel, and the other new tyre on the other rear wheel.

I'd have put both brand new tyres, assuming they are the same make and design, on the rear wheels and put the Pirelli on the spare. That way you'd have uniform grip and rolling characteristics on that axle.

What new tyres did you buy incidentally?

I had two brand new Michelin Energy tyres fitted to the rear of my C280 at the weekend (cost £146 all in) and, after running them in for a 100 miles or so it handles fine. It was a little skittish for the first few miles until the brand new rubber had worn its smooth shiny surface off.

Ron

 

[white-zed]

The way I read your post you now have one new tyre on your spare wheel, a used Pirelli on a rear wheel, and the other new tyre on the other rear wheel.

I'd have put both brand new tyres, assuming they are the same make and design, on the rear wheels and put the Pirelli on the spare. That way you'd have uniform grip and rolling characteristics on that axle.

What new tyres did you buy incidentally?

I had two brand new Michelin Energy tyres fitted to the rear of my C280 at the weekend (cost £146 all in) and, after running them in for a 100 miles or so it handles fine. It was a little skittish for the first few miles until the brand new rubber had worn its smooth shiny surface off.

Ron

hi ron i did have both new tyres on the back it's just my typing lol i had firestone tz200's fitted but have done nearly 200 miles on them now, but i travelled 40 miles up the m50 with no probs yesterday coming back down the m50 the back end felt like i had rear wheel steering in places,i'll let them bed in a little more and see if it cures the problem cheers for the help