My V8 was plagued with a cyclic wobble for the life of a particular set of
front tyres. Repeated balancing didn't cure it, but balancing on the stud
holes rather than the centre hole improved matters, as did locating the
wheel on the hub with two Rostyle wheel nuts before fitting the first two V8
nuts.
I found that on a long LH curve on the motorway the cycling would stop
(either vibrating or not) and on a long RH curve it would cycle faster. I
assumed that one wheel was reacting with the other to either cancel out or
double the wobble, which also implied that on the straight one wheel was
turning very slightly faster than the other. It occurs to me you may have a
similar 'front to back' situation i.e. you have imbalance both ends. Try
moving wheels round the car in various combinations.
PaulH.
http://freespace.virgin.net/paul.hunt1/
-----Original Message-----
From: Jason Dutt <jason@markerman.com>
To: MG List <mgs@autox.team.net>
Date: 15 April 1999 18:22
Subject: More Shaking Cars
>Hello, denziens of the list. Recently we saw a thread regarding a car with
>the shakes. My symptoms are a bit different, so I thought I'd seek further
>insight.
>
>Before I get in to the problem, let me create a scenario. The front and
>rear suspension on my 72 MGB have been completely rebuilt using a SPAX
>conversion on both ends. I have new Minilite Repro wheels with new tires
>that have been recently balanced on the dyno thingy the tire place uses.
>When the following symptoms first came up, I took the car back to the
>specialist who did all the aforementioned work. After checking for any
>goof-ups, and finding none, he suspected the drive shaft. Indeed, the
>bushings in the universal joint were shot, so he replaced them. This
>improved the situation, but the symptoms do still persist.
>
>So, with all that said, here's what's up. At about 60-65 MPH, and
>intermittent shake will appear, usually in the steering wheel. This shake
>will get worse as I accelerate, up to 75-80 MPH. Past 80 MPH, the shake
all
>but disappears, but I'm guessing it's just because the harmonics are just
so
>fast that I can't distinguish them anymore. Here's the weird part: The
>shake will move from the front to the rear of the car, then back again. In
>other words, it's not always in the front, or always in the back. It
>migrates. Sometimes, it doesn't shake at all.
>
>If you need any further info, please let me know, but I think this is all
>that's pertinent.
>
>Thanks in advance,
>
>=J=
>
|