http://quad4x4.com/Dodge%2094-04%20NV4500.htm"Losing" fifth gear is a common complaint from trailer towing 1994-1998 Dodge Ram owners and those with enhanced horsepower Cummins engines. The problem is less frequent on 1999 and newer trucks with the revised factory 5th gear nut. While the nut is often blamed, the part failing is really the factory mainshaft.
Due to a worldwide shortage of genuine New Venture parts (1994-2005 Cummins powered Dodge Ram truck) we will no longer be able to rebuild your NV4500 transmission as of December 2007. We will resume rebuilding NV4500 transmissions if and when quality parts again become available!