After driving my 98 4wd Tacoma up the interstate for several miles I get a scrubbing or squeaking noise coming from underneath that only occurs when you let off the accelerator. Normal driving around town the noise dissappears and after extende periods back on the open road it comes back. Any ideas?

 

Driveshaft sounds suspect to me...maybe a worn Ujoint? - unfortunatly the only way to check them is to take it off.

Keep us posted.