please help!!

i just noticed that when i change gears from reverse to drive the rear part of my car makes a loud clunking noise. also i noticed that when i hit above 70 miles an hour, pushing down on the gas pedal feels different- lots of vibrations and it feels like no matter how hard i'll push, it won't go faster.

a few months ago i had taken my car in to get the timing belt changed. i asked them to check out because it was making a loud squeaking noise when i reversed my car. the dealership told me it was a problem with my driveshaft, that i would have to get it replaced- but the squeaking went away so i dind't think of it again.

does anyone know if this is actually a problem with my drive shaft? has anyone else had this problem before? please advise! i'm afraid if i take it in, the dealership or mechanic will try to replace everything under the moon and i don't want to be swindled and would like to know probable causes before heading in there.

anything helps. thanks!

First thing to try IMO would be to put moly grease in all the fittings in both drive shafts, particularly the fitting for the sliding sleeve yoke. The sleeve yoke can cause the clunking you mention. If the grease doesn't help, check the bushings in the rear suspension for play.

The inability to go over 70 mph is probably a separate problem. Consider when the last time you changed the air filter, spark plugs, what brand plugs you installed, when was the last time you ran an injector cleaner through the gas tank, etc.