Jason:
Just for giggles, check the drive line for true. Get the car in the
air and check the trans output flange and diff input flange to make sure
that they are both true. Also check the driveshaft. A straight edge,
anchored would be accurate enough to see any run out.
The reason I mention this is that I bought a race car that had
vibration at speed. When I moved the components over to my vehicle, I
luckily noticed that the trans rear seal was pumping as the flange rotated.
It turns out the trans main shaft was bent (late 4 synch). Cause of the
bend has been suggested as crash damage, or perhaps jamming gears.
Certainly with the unknown history of many of our vehicles, a damaged
component can sneak in.
Good luck.
Kelvin.
> -----Original Message-----
> From: Jason Dutt [mailto:jason@markerman.com]
> Sent: Thursday, April 15, 1999 10:31 AM
> To: MG List
> Cc: Jason F Dutt
> 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=
>
|