any leaks? check all your hoses to transmission and look over bilge for tranny fluid. you may have a spliced line or over fill and tranny is not being lubricated.
also, you might check your propshaft and strut? if either is slightly bent, you will get whining and tranny vibration and that is very noticeable. early season riding tends to have more debris in the water from runoff and you could of hit an object unknowingly?
lastly, check your motor mounts. older malibus have lots of wood and you could have some dry rot that caught up over winter? off kilter motors will cause excessive trannywear, noise and vibration. check under carpeting where possible. the areas most prone to water damage are the stringer sidewalls in the engine compartment, the same areas that the motor mounts are located.
(Message edited by h20jnky on May 22, 2005)