[6pack] Trying to locate the source of a TR6 vibration

[Navarrette, Vance]

	Jim:

	I am inclined to agree with you. The issue seems to be one of two things in
my mind, tire balance or front wheel bearings. It doesn't happen in third,
because the tires are not rotating fast enough. If it were u-joints, I would
expect third and fourth to be similar, depending on the RPMS. Also, it doesn't
happen in fourth going up hill because it does not depend on throttle setting,
it depends on car speed, which stays flat or climbs very slowly when going up
hill.
	So here is my suggestion:

	1. Check your front wheel bearings for slop. Grab the top of the wheel with
both hands, place your feet against the bottom of the wheel and lean back
while tugging (pretty much your full body weight). If you feel the wheel rock
back and forth, then your wheel bearing is loose or worn out. Fix this first.
I have found that the Bentley manual is incorrect in the wheel bearing setup.
Bentley mentions something about "back off one flat" when tightening the
castle nut. I feel this is just "flat" wrong (Har-har-har. I crack myself
up!). Finger tighten the castle nut, but do not back off one flat.
	2. Have your tires balanced WITH THE TRIM RINGS ON THE WHEELS. If you don't
have trim rings then this is not as big a deal. My experience is that tire
shops take the trim off to balance the wheel, then puts the trim back on
ASSuming that the trim will not affect the balance. WRONG! Ask me how I know.

    Vance Navarrette
    Cogito Ergo Zoom
    I think, therefore I go fast

-----Original Message-----
From: 6pack-bounces at autox.team.net [mailto:6pack-bounces at autox.team.net] On
Behalf Of jim hearn
Sent: Wednesday, June 24, 2009 8:00 AM
To: 'Todd Bermudez'; '6 Digest'
Subject: Re: [6pack] Trying to locate the source of a TR6 vibration

My first suspects for the vibration were the tires and/or the drive
shaft, but the conditions under which it vibrates would seem to
eliminate these two sources and I'm not sure but doesn't it also
eliminate the u-joints since why doesn't it vibrate accelerating on the
flat in third gear?  Jim