I've had lots of experience with out-of-balance wheels/tires over the years.
But, none as puzzling as this most recent episode: I had four 20 minute
sessions with my MGB on track at Summit Point on Thursday as part of the
SVRA Driver Orientation Program. The B ran really well but suffered from
intense vibration from 70 to 90 mph. The vibration on the last 1/3 of the
main straight was worse than anything I've ever had before.
The wheels (Minator alloy) & tires (Dunlop's) were balanced carefully by my
friends at SascoSports.
So, I doubt they were the cause. Although we didn't recheck them yet.
New bearings were installed last week.
Shocks are in good condition & had HD valves installed & fluid topped off a
few days before.
New V8 bushings were professionally installed about a year ago.
One worn tie-rod end was installed last year. The other still feels tight.
Steering rack is well lubed & damper is tight, probably too tight right now
as I put in a shim.
Input to the steering wheel is directly responsive at the wheels.
The driveshaft was balanced last week too.
So, everything seems tight & shouldn't cause or magnify any imbalance. But
it's there. In fact, even after Dave at Sasco carefully balanced my street
wire wheels on Friday, I couldn't do more than 65 on the Interstates coming
home without the vibration occuring.
Anyone have any ideas? Anything we may have overlooked?
Norm Sippel
'66 MGB
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