Hey guys,

Got an NV4500 with a divorced NP205 on it's way. I think I'm gonna add the auxilliary underdrive unit before the transfer case so I can have all gears in 4wd as well. Opinions?

I have a 2nd gen bellhousing, pedels, hydraulics, and flywheel. My questions are:

Will I be able to use these pedals? (automatic now)

What bang for the buck clutch should I get? Lookin for 400hp most likely. will a 1947 CON OFE from a 2001 work??

Will the 2nd Gen flywheel work?!

Thanks in advance.

 

I would think everything will work except the pedals and you should be able to put a second gen clutch in it. I believe the pedals a upper portion of the hydrulics will need to be from a first gen.

 

as long as you know the input shaft size, i think you could get a clutch for any year models of the nv4500. they all had 1 1/4" inputs. unless you find some that have had the 1 3/8" input swapped into it of course.

 

will a 1st gen clutch work? 2001 6 speed (5600?) work? Or only specific for 4500s. Thanks for the responses guys.

 

Ok, found out from the Valair website that the 2nd gen flywheels are all 12.25". All 12.25" clutches for 88-05 cummins work as long as it wasn't the HO (which had the NV5600 6 speed). I can put on the 1st gen 13" flywheel, but there are not as many clutch options it seems. For 12.25" flywheels there are way more options at least through Valair. They seem to have much more managable prices than Southbend.

Also found out that the OE replacement (not button type I think) for the NV4500 is good for "300hp and 700ft-lb". I think I'll be going with the midrange option. From the site:

Attention all 12-1/4" NV4500 users
... You no longer need to upgrade to a 13" clutch, with our new HD Spring Discs you will never have to worry about breaking the clutch hub or springs like on the OE version. The new 'Floating' designed hub minimises clutch rattle when idling in neutral with the clutch pedal released. Avaliable in Organic Facing, Ceramic Button, Kevlar Button and Kevlar/Ceramic Button.

 

Please don't waste money on a 12 1/4" clutch. The centers are fragile and prone to breakage from 1st gen bottom end torque.

 

Dave, is this including these "button" type from Valair? I have to machine out a groove for the inner 7" of diameter of flywheel because they have a thicker section in the middle of the clutch.

Anyone know about these upgraded 12 1/4" type clutches? Am I doomed to get a new flywheel as well?

 

I looked at it and it looks somewhat better designed than the 12 1/4" Con-O I had that broke.

Are you planning to tow with this thing when it's built?

 

Someday perhaps. As of now my only foreseeable tows will be a lobsterboat twice a year. Anything other than that probably wouldn't add up to more than 7-8,000lb or so I'm guessing.

Did that blow on you when engaging or when engaged?

They wrote on their site that they have upgraded the 12 1/4" clutches so the 13" upgrade is no longer needed? However, I am a bit ignorant on these issues untill my recent research. So I have nil experience and appreciate all input!

 

I don't know when it broke, it just started making bad noises and vibrating like I had lunched the input shaft bearing on the trans. I was relieved when it turned out the be the clutch. Truck was still driveable, the clutch never slipped.

 

Stay with a 13" clutch.