I had this annoying situation also. Complete front end overhaul in my
restoration. Steel wheels (TR6) issue. Always between 50-55 mph. Then I
found the problem. Quite simple and relatively easy to find and fix. The
problem was with the hub itself. Ran a straight edge across the flat of the
hub between the studs. Nice little rocking effect. One wheel out .035" the
other .070" via runout gauge. Removed the hub and had the face turned on a
lathe at work (after removing studs). Replaced them and no shimmy from 0-100
mph. Checked this on my TR3A restoration and found the same thing to a
slightly lesser degree. Applied same lathe work and mounted my new wire
wheels with bias white walls. Balancing done by Steele Motors in PA. Upon
start up and go 0-90mph no shimmy. Just another thing to look for. I have
shared this with a few others who discovered the same thing. Had the hubs
turned and the shimmy went away. Just FYI.
Alex Manzo
72 TR6
59 TR3A
----- Original Message -----
From: <DLylis@aol.com>
To: <Kinderlehrer@comcast.net>; <nogera@worldnet.att.net>;
<Triumphs@autox.team.net>
Sent: Thursday, November 01, 2007 7:28 AM
Subject: Re: [TR] Wheel Shimmy
>I assume that the Morgan owners all have wire wheels? Accelerating,
> although it may seem counterintuitive, actually makes sense. Decelerating
> may/probably/will have the same effect. I will bet that the vibration is
> set up at 55
> - 60 mph and goes away as you accelerate through that. This is a very
> common malady and can, and does, occur with steel wheels as well. This
> can be
> trued and balanced out. This is a "harmonic" set up at that rotational
> speed.
> Wouldn't you think that it would get worse as the rotational speed
> increases?
> For the most part it doesn't. I have had it at 55 - 60 but the car
> settles
> down as I approach 70 -80-90 mph. The annoying part is that you drive
> most
> of the time at 55 - 60. I have allowed myself some "wiggle room" in my
> statements because sometimes the wheel is so far out that it does not
> conform to
> what I have said here.
> I am by no means an officianado on Morgans, in fact know very little about
> them. What I recommend is that you call Alan Hendrix at Hendrix Wire
> Wheel.
> NFI. He talks for free. He trues and balances for cash. He can help
> you
> understand this phenomenon, as he did with me.
> He may confirm that Morgan has an inherent flaw that causes wheel shimmy,
> but I were a betting man I would bet not. I may lose!
>
> David Lylis
> 69 TR6 CC26160L
> 60 TR3A TS74461LO
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