Hi folks-John Blair reciently posted questions concerning owners
manual, vibration and tires.
I reciently asked about a manual for my +4 on this list and was told to
contact Malvern. I did but they were off on Easter holliday(the whole week
after Easter) so Icalled Melvin Reutter who had a +4 manualwhich cost me
9.51 lbs which I assume is around $5000 us! I am sure that a similar manual
is available for 4/4. It's only 43 pages long. The owners manual on my
wifes new car needs that many pages to tell you how to use the sound
system! Anyway, one the last page of the Morgan manual is a short piece on
"Road Vibration" It was prepared by ISIS Imports (CA) and besides it refers
to "tires" and not "tyres". In the introductory paragraph it states;
"Uneven road surfaces in the Unites States, and the extensive use
of radial ply tires, contribute to front wheel "shimmy" or excessive
speed-related vibration in a Morgan. This vibration, at speeds from 45-50
mph and 55-60 mph, can have several causes. The following suggestions are
offered to assist in solving this problem":
1. Wheel alignment should be set from 1/8-3/16" of toe in. Toe out, even
the smallest degree is to be avoided.
2. dynamically balance all four wheels.
3. Insure that all wheels are "true".
There then follows a 6 point check of the front end.
There is no mention of tire type in the manual but it does list some tire
pressures. For example 16-18 psi for normal driving and to add 6psi for
highway. Granted this is for bias ply tires but I don't remember running
that soft back when Iwa using bias ply tires except when dreg racing-but
thats another story.
When I used to work in a garage in the late 50's we always balanced tires
on the car. You would accelerate the wheel to apros 55 mph and then add or
subtract weight by monitering the shimmy.
John-I'll fax you the above referenced page. When I get some time next week
I'll scan it and see if I can get it archived.
Hope this is of assistance.
Dave McCoy
--
G. David McCoy, PhD Dept. of Environmental Health Sciences
gdm@po.cwru.edu School of Medicine
ph(216) 368 5963 Case Western Reserve University
fx(216) 368 3194 10900 Euclid Ave. Cleveland, OH 44106-4940
|