Bud,
Cupping is usually cause by faulty shocks and needing the tires rebalance.
The Scrubbing is cause by being out of alignment, your toe in is out of
adjustment. Shocks should stop rebound halfway through the first cycle on
rebound. Unfortunately you will need to put the front tires on the back if
you want any more service out of them. But I would suggest that you replace
the shocks and tires then have the front end aligned. As far as a four
wheel alignment, most competent shops that have the computer/laser systems
should be able to check the rear alignment when they do the fronts, they
may not be able or willing to attempt to adjust the rear because of the age
of the car and the scarcity of locally obtainable parts. But it can be done
with shinning the trailing arms or removing shims until it is aligned.
When you rotate radial tires, the front tires drop straight back to the rear
and the rears to the front.
I hope that this answers all your questions satisfactorily.
Larry Zink
Z Group Racing And Performance
1964 Spitfire4 Mk1
Houston, Texas
-----Original Message-----
From: Bud Rolofson <Bud_Rolofson@nps.gov>
To: triumphs@autox.team.net <triumphs@autox.team.net>
Date: Tuesday, July 21, 1998 2:49 PM
Subject: Tire Concerns TR6
>
>I noticed that when I run my hand over my front tires I can feel a slight
>"cupping" effect on the outer edge of the tires (Avons). I ran my hand
over the
>tread of both the front and back tires and the back tires don't have any
cupping
>and are smooth. At this point it's a very slight affect but one that I'd
like
>to correct before it causes any more uneven tire wear. I was told by a
friend
>that it is a sign that the front shocks might be worn. I did the
sophisticated
>bounce test and got about 3-4 after letting loose of the front bumper. The
>tires have about 3000 miles on them.
>
>I'm also getting a little tire scuff or tire squeal when I do a tight
(steering
>wheel at the left or right lock) turn. I assume that's not normal.
>
>1) Is the cupping and scuffing one problem or individual problems?
>
>2) Is either problem a sign that I need an alignment (the car runs a
straight
>line and the front end was totally rebuilt recently...approx. 3500 miles
ago)?
>
>2) Does one always do a four wheel alignment on a TR6 or can you just do
the
>fronts separately?
>
>4) I'm going to rotate the tires but would like to cure the cupping problem
>first.
>
>I'd appreciate any suggestions on possible causes and cures.
>
>5) Also is there a right way to rotate the tires (four, since the spare is
>different) front to back, or diagonally?
>
>Thanks for the help.
>Bud 71 TR6 CC57365
|