rear tyre wear

[gar v70]

any ideas what will cause both back tyres to wear on the outside edge, had all the tracking done when I put new tyres on about 6 months ago

[oragex]

Both edges on each tire, or only the edge towards the side of the of the car ? Could you upload a picture ? How many miles on it ?

[bkulcsar]

I had the same problem about 2 years ago.
Fixed it by replacing about 90% of the bushes. It was a bit pricey, but I intend to keep the car for at least 5 more years.

[MarvinMitt]

Check your trailing arm front bushes.
Mine had big play in them when I rocked the rear wheels front to back with bare hands so the wheel alignment was giving.

[ASt85]

The wear on the inner edge is caused by poor alignment settings, such as excessive toe and/or caster settings ie the wheels are most likely running with the arms set to to great a caster angle - this may or may not be identified by a four wheel alignment check which usually only checks the toe in/toe out of the back wheels.

Whilst too great a toe out will cause the inner edges to wear more rapidly, it could be caused by poor springs/shocks changing the rear camber angles so that there is more load placed on the inner edge of the tyres.

[gar v70]

Originally Posted by ASt85

The wear on the inner edge is caused by poor alignment settings, such as excessive toe and/or caster settings ie the wheels are most likely running with the arms set to to great a caster angle - this may or may not be identified by a four wheel alignment check which usually only checks the toe in/toe out of the back wheels.

Whilst too great a toe out will cause the inner edges to wear more rapidly, it could be caused by poor springs/shocks changing the rear camber angles so that there is more load placed on the inner edge of the tyres.

thanks but its the outside edge not inner

[gar v70]

Originally Posted by oragex

Both edges on each tire, or only the edge towards the side of the of the car ? Could you upload a picture ? How many miles on it ?

both back tyres, both on the outside edge, car has done 201000, tyres approx. 3000

[ASt85]

Originally Posted by gar v70

thanks but its the outside edge not inner

It could still be the camber angle but with the outer edge too far tucked in a bit like the early Triumph Heralds and Spitfires - do the rear wheels look vertical in comparison with the body ie do they look as though the top of the tyre is a little too far out or too close to the wheel arch when stationary?

[oragex]

Yes, the rear geometry needs be inspected by a Volvo specialist. The trailing arm can be worn - or even have a crack on the metal. Not common but happens - even more so if a previous owner went replacing the bushes for some reason and installed cheap ones.

Does the rear of the car sit higher than normal? Were rear springs/shock absorbers replaced in the past ?

[100K+]

I had a 2002 V70 T5 with your issue. Its totally counter intuitive to what you'd expect. The wear on the rears was not too bad however, and again counter intuitively the fronts wore on their inner shoulders.
I just used to swap the wheels diagonally and front to back. Worked for me for some 100K+ miles until she was scraped @ 240K

Cheers
Bob