Vibration in steering

[MHLIGGINS@aol.com]

<<Same shop,(good and decent shop)advises the RF wheel is bent and need new
wheel. Go to junk yard and get a good condition wheel.  Now, notice different
kind of vibration when braking and more importantly when not braking and on
the highway around 40-50 mph.>>

	I'm just going to relate some things I know.  Volvo wheels do seem to bend
easily.  I have an '85 744T, and two of the 15" wheels are bent.  (One of the
hardest things to find in a parts yards around here is a set of GOOD 15" Volvo
wheels.)  My Volvo wheels are bent enough that you can see it rather easily,
and the vibration is noticeable.
	The black quat has 15" Fuchs wheels, one of them is bent slightly.  It is not
noticeable immediately after they are balanced, but as the tire wears the
imbalance can be felt.  If it's on the front you can feel it in the steering
wheel.  On the back it's barely perceptible, except by auto "enthusiasts".
	You also mention hitting something in the road.  If it was hard enough to
bend one wheel, it was hard enough to bend two.  If the shop changed one tire,
then rotated that wheel to the rear, the rear wheel should have been rotated
to the front.  Then it would be noticeable if it were even slightly out of
round.

	Also, it's possible to break belts in steel belted radials.  When that
happens, they can get unbalanced.  This can also be an intermittent problem -
sometimes it's out of line and vibrates, other times it's not.  If it's on the
front end of the car you can also get some severe back-and-forth motion in the
steering wheel at low speeds.  If a belt was broken on the back tire, again,
it should have been rotated to the front -- thus making it more obvious.

	Third item is WRT the braking situation.  This sounds like one or more warped
rotors.  Volvos are well known in this area for cooking the front calipers.
So much so that it's one of the few calipers that's kept in stock at the local
shops.  Most other cars they just keep the rebuild kits around.  If the front
rotors are cooked, they will overheat the rotors.  Significantly.  That can
lead to warpage.  So can overtightening the lug nuts.  So can hitting a puddle
with hot brakes.  And so can some other things.  

	Also, the 40-50 mph bracket generally indicates that a wheel is out of
balance.  It should also be noticeable again at about 70 mph.

	Those are the things I'd look into.

	Later.
	--ml