ZF-5 vs NV4500

[nick112207]

Ok so whats the deal?

I can honestly say the whole time i've been on here, i've NEVER come across a thread about someone blowing up their ZF-5. On the other hand, on my Cummins side of the world, it seems like at least once a week there is a post about someone blowing up their NV, losing a gear, breaking an input shaft, etc.

Now as i understand it the ZF is an aluminum case tranny, where as the NV is a cast iron tranny. As i also understand it though the NV is basically just a gas tranny stuck behind a diesel engine.

Why don't i ever see issues with the ZF? is it an actual diesel tranny? or does it have to do with the difference in torque going through the tranny from Powerstroke, vs the torque of the Cummins going through the NV?

[nick112207]

no one knows?

[Jake]

I don't. I was wanting to know too.

[SodaPop]

Well i dont know if this helps but i have a friend that has a twin turbo 2001 cummins with the nv five speed. He has torn out first, third, fifth, twisted the imput shaft and cracked the case. All in the last year and a half. I also have a friend that did a cummins conversion in his superduty and has it bolted to a zf5. He also has twins and a bunch of other mods injectors, fass pump, smarty and edge, ect. Neither of the trucks have been put on the dyno but seem to run very close in power. Down the track they are neck and neck. The ZF has had no problems thus far. I am bolting a 12v cummins to my ZF6 and going for 550 horse on fuel so well see how she holds. I am told it will just keep asking for more. Right up to about 750hp. LOL well see Sorry if there is a bunch of typos im in a hurry just home for lunch.

[dsljnky]

i know a few people who have junked the nv4500 in favor for a ford tranny behind their cummins.

[nick112207]

yeah but why? is it that much stronger than the NV4500? is it an actual diesel tranny?

[dsljnky]

Originally Posted by nick112207

yeah but why? is it that much stronger than the NV4500? is it an actual diesel tranny?

If I understand correctly, and i may be wrong, but the nv4500 behind a diesel is a gasser trans with bigger input and output shafts.
My friends little brother just broke the input shaft off in his 99 cummins, i guess it pushed everything backwards when he did it and cracked the tail housing too.