Having recently got the truck back from having a seal replaced on the transmission I have now noticed that there is a rough knocking sound when stationary in 1,2,D,R. The truck drives good and the noise goes away when moving (or I just cant here it due to the higher RPMs as I'm moving). When stationary in N and P there is no noise. All changes seem OK just don't know what the noise is, any ideas ?
(I can't remember whether it made the noise before the replacement seal). Thanks........