Divorced NP 205 input drive options

[Barrman]

Trying to put the NP205 behind the 6BT/Getrag in the truck for Sermis. Trying to use stock front and rear drive shafts. That means there is about 1 inch between the rear yoke of the long transmission and the input yoke on the 205.

I don't know the answer to this which is why I am asking. Does there have to be a drive shaft between them? Does there have to be a Cardin Joint? Why can't I just move the tcase up so a single ujoint will bolt to both units and be done?

Thanks.

[m715]

I have wondered about that as well in the past and remember reading that the spud shaft with 2 u-joints will accommodate minor angle variations and the driveline flex/torque where 1 u-joint will not. With 1 u-joint there can be no angle at all between the trans and tcase or there will be vibration, in general people seem to avoid a single u-joint. I have seen people use a CV joint instead of a spud shaft. I'll see if I can find the build where they were talking about it...

[m715]

Missed my 5 min edit window...

Here is a couple of older threads talking about it...

Divorced Doubler T-Case
http://www.pirate4x4.com/forum/showthread.php?t=154113

How could I mount a divorced 205 in my truck?
http://www.ifsja.org/forums/vb/showthread.php?t=48046

1995 crew cab dually chevy getting a 1997 5.9l/Allison/Brownlipe
http://www.4btswaps.com/forum/showth...rownlipe/page2

Some say yes you can use a single u-joint, but angles need to be dead on and the trans and transfer case should be in the same cradle so they can't flex differently

[Mikel]

If you switch the front and rear driveshafts, how much would that move the transfer case backwards??

[k8icu]

I think the answer is a drive shaft was used for flex. If off roading (which I would assume Sermis would be doing) if you get some flex in the frame the two u-joints will work and keep on going where as the one may not be able to handle it. Just a laymens view but it makes sense to me. Can you do what Mikel suggests? Or you may have to have drive shafts made.

[Barrman]

Thanks for the links and suggestions.

Yes Sermis plans to take it off road. He also drives everything like he stole it. Flex is going to happen. I will measure the shafts and see if I can swap them.

[brute4c]

Ditto on the 1 joint...that is what I have heard several times.

The front driveshaft is so much smaller in diameter than the rear, I dont know that it would be good for using on the rear...for half the power when in 4wd--ok...for full power in 2wd and highway speeds....especially with a lead foot...maybe not.

I think shortening the shaft a little is a solid idea...that and re-balancing...or making another one...

[SVENG52]

Since we're talking about the stub shaft does anyone know what the u-joint size is?

[brute4c]

All the stock joints are #369...specs on this page:

http://www.summitracing.com/parts/PCN-369/

[tndonor]

I had a 1980 Jeep J10 with a Cummins 4BT, NV4500, Dana 300 and a divorced NP205. I used a splined shaft to accomodate the flex from power (was a P pumped 4B haha) and off road.

My feelings on the matter were in a perfect world, it may work I dont know. But with the torque of a Cummins, hard driving professed by the driver, and intentions of off roading.....I would use the proven method.