Re: drivetrain thumping

[Scott Fisher <sfisher71@domain.elided>]

--- Brian's mail <bsmith@domain.elided> wrote:
> I have an 82 Spider that is making a rhythmic
> thumping sound, seemingly
> against the floorboards or drivetrain tunnel on
> acceleration ,especially
> when tight turning.  I replaced the doughnut
> (broken) but the sound
> persists.  Any thoughts ?  Transmission mount ? 
> Motor mounts ?

Check the bushing where the big T-arm connects to the
top of the diff.  I had a similar thumping sound at an
ARA autocross and the T-arm bushing was suggested as a
likely suspect by those with more experience competing
in Alfas than I had then.  

I no longer have that car, and never did replace that
bushing, so I can't conclusively say that that was IT.
 But it's another likely candidate, as deflection
there could cause a thump under the conditions you
describe.

--Scott Fisher
  Tualatin, Oregon
Send FREE video emails in Yahoo! Mail!
http://promo.yahoo.com/videomail/

--
to be removed from alfa, see /bin/digest-subs.cgi
or email "unsubscribe alfa" to majordomo@domain.elided