well ran into a few problems with my truck the gas gauge doesnt read correctly when i turn off the ignition the needle goes all the way down and turn it on it goes up when tank is full needle is all the way up but once it starts getting low to 3/4 mark it stops. is it the sending unit? and the drive shaft rumbles like crazy on freeway but anything lower then 50mph its quite and not so bad of a rumble not sure what it it possibly yokes worn out it is a double cardon shaft and called a drive shaft shop to inspect it but would like to know if possible d.i.y