Ok here is the deal.

Just bought new wheels and tires recently....everything was fine except for a slight vibration from the rear tires at 70mph.

Lately it has gotten worse....now I get the vibration at 65+mph (feel it in the seat and through the stick)....and now, at about 40-45mph I get a low speed vibration through the same areas. I vibrates enough at these low speeds to do a chocolate milk commercial..... It only does this when the clutch is out and I am accel/decel in any gear......when I put the clutch in and "neutral" it...it goes away...so I am assuming it is in the driveline?

I have re-torqued the lugs on the wheels to make sure, and accounted for all wheel weights and normal tire wear thus far. The weight is still on the driveshaft....and I see no leaks around the pinion seal or tailhousing seal where it might be out of round......any suggestions people??

 

Bad tranny mount??

 

Or it could be bad ujoints. Check those as well.