sound from trans to rear end ever 5 miles last about 5 sec.replaced u joints on 2003 Lincoln Town Car

have had lincolns 25 years and limo co. do repair not seen any thing like this before

1 answer
Need more description/conditions in order to answer this. Speed , load condition, turning , straight only, gear selection make a difference? what if any diagnostics (besides u-joint replacement) has been done . Did u-joint replacement have ANY effect on symptoms?