Ok guys 1988 formula 350 was sitting 9 years runs good now noticed a humming when on road thought rearend so replaced fluid put new tailshaft bushing and seal have it on stands now still hums after about 20mph gets louder as it increases speed no vibration aluminum driveshaft and stock ujoints but seem tight and pinion seems tight any idea im stumped when under car it seems loudest in center of driveshaft please help

 

It's impossible to tell anything about U-joints by "seems tight". They'll "seem tight" up until the minute the thing falls down to the ground.

Replace them.

 

Ok cool will they create that humming sound its pretty loud if windows r down u can hear it

 

Well, they absolutely "can". Not sure about "will".

They're a guaranteed-to-fail wear item and pretty cheeeeeeeeeeeeeep... if you haven't changed em lately, just do it.

 

Ok will do this weekend ill let u kno what it does

 

Ok been busy but got ujoints replaced no change in noise pls help

 

Im lost my only other idea is maybe the pinion bearing is dry and makeing a rubbing sount that is magnified by the aluminum driveshaft but there is no play in it at all car has been sitting for 10 years is there anyway to check it or lube it without dissasymboling the rearend i thought it was lubed by the diff fluid ive only put about 10miles on the car since i got it just to see how everything held up