We have eliminated the tires and wheels. My mechanic is saying that it
is the control arm bushings. I concerned because the vibration only
happens at 70+mph and can't be felt through the stearing wheel.
I feel it through the seat and can see arm rest vibrating.
I thought that if it were in the front end I would feel it in the
Tom, my dad sold tires for several decades; I sold cars for 30+ years;
we were both highly sensitive to non-smooth riding tires. The number 1
cause of vibration such as you describe, AFTER spin-balancing tires, was
tires being out-of-round.
Just because you tried 2 different tire sets doesn't eliminate this
possibility. And it is easy to verify yourself.
Your description indicates a rear vs. front end problem. Assuming
so, check the rear tires for *out of round* ; remember, a box can be
installed onto an axle, spin-balanced, and rotate smoothly--and yet it
definitely won't ride smooth!
Check them by raising them just an inch or so above ground. Lay an oil
bottle (or 10-inch block of 2X4) squarely on its side and up close to a
spin the tire, by hand, and watch how close the tire's circumference
approaches the stationary *reference object* as it rotates. High spots will
narrow the gap, and low spots will widen the space(DUH!). If found out of
round, have them trued and then balanced, and enjoy the quiet, smooth ride
Lesabres are capable of.
If all tires were so checked, my bet is a surprisingly high % of them
would show excessive out-of-round. Such tires will often ride smoothly at
all but certain speed-ranges. Only those w/o excessive runout will ride
smoothly at all speed ranges.
Either way there are times the suspension components on one care can absorb
tire/wheel eccentricities, other cars with alloy components cannot. Find a
shop with the new Hunter road force variation type wheel balancer.
Thx, Shep, for the enlightenment. Just for my info, what does this
balancer look like? And, what (apparently) different principle(s) does it
use as compared to more conventional balancers?
Though I'm retired, I'm still quite sensitive to, and still greatly
dislike, rough-riding tires.
Gotta relate a short story to you: bought a *new* 2003 Sonoma in
February, disliked the looks of the factory aluminum wheels and new tires,
altho' they rode perfect at all speed ranges(unusual). Found a
nicer-looking set of S-10 wheels with nice Michelins on a wrecked pickup in
a wrecking yard for $250!!! Installed them and they ride better than the
others, due to the Michelin's superior quality/design; plus, the
unbelieveable part is they have NO vibration or out-of-balance
symptoms--again, straight off a wrecked truck. Not my normal kind of luck.
Thanks again for the info. s
This balance applies a rolling force to the tires as they are spun, the
variation in the construction of the tire also varies the force the tire
exerts against the rollers, this translates into a degree of road force
variation, overt a certain reading the tire cannot be compenasated for by
any balancing and would be replaced. Semi retired here, 25 years with GM.
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