740 Estate - Rear Axle Bushes

I noticed over the weekend that my car tends to pull left under acceleration
and veer to the right when I take my foot off the throttle. There is no
movement of the steering wheel and the effect is very slight. The car
doesn't change direction when braking. I have come to the conclusion that
the rear axle must be moving around more than it should.

Having jacked the car up this evening, there's nothing obvious wrong with
the bushes for the trailing arms, torque bars or panhard rod, but they do
all look like they have been there for a long time.

Has anyone out there suffered from this problem and, if so, how did you fix
it?

Many Thanks

Steve

 

Renew all suspension bushings (front and rear) with Polyurethane bushings.
If you are in UK (which I suspect by your addy) visit the following URL.
http://www.racecar.co.uk/superflex/index.html this is the contact point for
Superflex Polyurethane bushings.

All the best, Peter.

700/900/90 Register Keeper,
Volvo Owners Club (UK).

 

It dawned on me yesterday that the symptoms of this problem only began after
I bought a new tyre (following a puncture). When I measured the diameter of
the new tyre and compared it to the tyre on the other side, the new one was
6mm bigger (just from normal tread wear). Summising that if the car is
fitted with a limited slip differential, under power the offside wheel would
travel around 20mm further than the nearside, and under deceleration, the
diferential would free up and remove the one sided drive effect.

So I swapped the front wheels for the back ones (fronts fitted as a pair and
of equal diameter) and, hey presto, the problem has gone away. I would
never have believed that such a small difference in tyre diameter would
cause such a significant effect on the steering. Also, it turns out that I
have a limited slip differential, which is nice!

No need to change the bushes after all!

Steve

 

Your bushings are still probably shot, with good bushings you shouldn't get
a significant effect from such a slight tire mismatch.

 

Always make sure the tyres across front or back are equal with the same
tread pattern and same pressure .Its wise to have the same pattern all round
but if that's not possible the same pattern should be on the front wheels
and same on the back wheels ,never mix tyres on the same axle.On new radials
low pressure is not easy to pick but come a long hot run and any tyre thats
been abused will blow out .