The NV3500 transmission was first manufactured in 1988 and was known as an HM290. It was installed in GM trucks and eventually re-designated as the 5LM60, which had two different designs. The 290 and the 5LM60 had four shift rails. The NV3500 is manufactured for both four-wheel drive and two-wheel drive vehicles. The current NV3500 is found in full size GM trucks from 1988 and newer, S10 trucks from 1990 and newer, and Dodge Dakota V8 Ram trucks from 1994 and newer. The NV3500 is a five-speed manual transmission.
Check the shift rail on the transmission. This particular transmission has a single shift rail, instead of a rail for each gear. All three shift forks are mounted on the shaft. The shaft is supported – in the front and rear housings – by bushings and one linear ball bearing.
Look at the body of the transmission. It has a front half and a back half. You can see where it comes apart between the two halves, as you must split it where it comes apart to service it. The front and back halves are both aluminum.
Locate the plugs. The NV3500 has a fill plug on the front housing, on the passenger side. It also has a drain plug on the bottom of the front housing.
Look at the overall shape of the transmission. The bellhousing, where it mounts to the engine, is larger in diameter than the tailshaft. The shifter is located on the back half of the transmission.
