Thumping upon acceleration
In my '91 Spider Veloce I am getting a thumping sound from what sounds like the rear. The sound happens only on starting off from a standstill in first gear. It seems more pronounced on making a turn from a standstill, either right or left, and is only in first gear. The thumping sound is a fairly rapid "pum, pum, pum , pum, pum," and ends quickly.
I just finished installing new rear shocks and springs. Any ideas? Thanks.