The NV-5600 was originally standard behind the high-output 5.9L Cummins engine. The early NV-5600 version, which was produced from 1998 midway thru 2000 is known to have synchronizer problems and a weak input shaft. In 2001, the NV-5600 received an upgraded clutch, input shaft, and improved synchro design. This was in response to many issues owners had regarding these components, especially while towing heavy loads. All of our NV-5600 units are completely upgraded and are backed by a warranty depending on your needs.
Improved version introduced in 2001; Upgraded Synchros, Clutch, & Input Shaft
DO NOT USE ROYAL PURPLE
5 Most Common NV-5600 Manual Transmission Problems
Noise when accelerating, noise when decelerating
Difficult to shift into gear
Grinding when shifting into gear
Jumping out of gear
Will NOT shift from gear to gear
Noise when accelerating, noise when decelerating: Issues associated within this category are generally associated with the NV-5600 input or pocket bearing malfunction, sixth gear failing, and the pilot bearing could also fail.
Difficult to shift into gear: This problem is common in the NV5600, this transmission is more like a large 18-wheeler transmission, double clutching at the right RPMs is key to resolving this problem. Additionally, you might have a Clutch hydraulics issue requiring that you replace these elements.
Grinding when shifting gears: This issue can be excessive wear of Syncro rings as well as excessive bearing wear
Jumping out of gear: This problem may be related to worn synchro rings, synchro sliders, gears, and/or shaft movements caused by extreme bearing wear.
Will not shift from gear to gear: Fluid varnish build-up around the shift rail bushing exacerbates this problem. We recommend you to have regular NV-5600 transmission maintenance. NV-5600 transmission fluid is extremely expensive at the dealer, call 901-278-0090
