So my nv4500 is now apart, snapped input shaft, warped main shaft and counter shaft. Was told by a transmission specialist he had never even seen a input shaft break on a nv4500 and cant understand why the rest is all twisted up. His only thought was maybe the bell housing bolts were loose or dowel pins were missing but the bolts were tight and dowel pins were there. The bearing on the input shaft was pretty well shot, could that have been the cause of this or should I be getting some beefier parts?
When this all went down i rolled onto the throttle at 50 mph and thats when the input shaft let go. Im also running 37's and im not sure where im at as far as torque goes but i only see more torque being applied in the future, so if anyone has any suggestions on how I should upgrade this tranny any better other than the 1 3/8 input shaft that would be great. Thanks

 

Just my opinion but I'd say spend the extra coin for some billet shafts now. If you're going to be adding more power later you'll just be tearing the tranny apart again.

 

Happen to know of any good sites to look for some? Wish I have had my truck on a dyno before this, it would be nice to know where im at

 

Just a few. There are lots of em out there.
cumminsperformanceparts.com
dieselpowerproducts.com
puredieselpower.com

 

get a 6 speed

 

X2 build it once, build it right!

 

Well I got a fully splined billet main shaft, 1 3/8" billet input and counter shaft, new gears and syncros, cast iron rear extension and the whole 9 yards. Anyone ever try those fast coolers that take place of the stock pto cover? they worth the money?