grinding sounds!!

[jmeti000]

whenever i let on and off the throttle i get a grinding sound for the first couple of seconds and then it goes away...sounds lounder when i let off the gas, and gets louder as i go faster. i took it to the dealer and they didnt do a darn thing. they said my driveshaft was pretty steep from the lift. no checking fluids, dropping the differential over..etc...NOTHING!! the u-joints have been checked and they are all ok. apparently i have quite a bit of backlash. could this be causing the grinding?? and how do i fix it? any help would be great..
thanks
jacqui

 

[stallion85]

Do you have a 4 speed manual? Mine does the same thing and I have been told it was the input shaft bearing going bad on the tranny. Mine only does it at 45 MPH and higher when I let off the thorttle

 

[jmeti000]

its an automatic, but the grinding becomes really noticable around 45 like you said.