To add to above, I'd ensure that all halfshaft bolts are tight. (Assume you've checked already but happened to me once). Good luck, curious what you eventually find.
PANTERA INTERNATIONAL
A DE TOMASO CAR CLUB
Presents the De Tomaso Forums
The On-Line Meeting Place for De Tomaso Owners and Enthusiasts From Around the World
Clicking on the banner will take you to the sponsor's website.