Can I add a divorced NP205 with only a u-joint (no shaft) in between?

[knaffie]

I'm trying to lengthen my driveline and get some more gearing combinations. Ideally, making it 15" longer would be perfect. If I go more than that, I'm going to have angle problems in the rear worse than I do in the front now. A 14" long 205 would be perfect, but if I need to add a 6" driveshaft in between them, I will be too far back.

So can I connect the rear output 1350 yoke on my 231 to the front input 1350 yoke with just a 1350 u-joint?

[MuddyV8YJ]

does your 231 have a fixed or slip yoke?

theoretically, it can be done. but if you have any movement, parts are going to be very unhappy.

[knaffie]

I put a SYE on my 231. I understand I'd have to VERY rigidly mount everything. Hmmm. Risky. But maybe its been done before?

[Balsax]

There has to be room for thermal expansion. It can chew up your u-joint or bearings in the transfer case otherwise.

[HsOffRoad]

I don't know about this thermal expansion business. There's no provision for so called "thermal expansion" where the factory t-case bolts to the tranny, or when you run a doubler or marlin dual case setup. I mean, perhaps the splined coupling allows the shafts to change length slightly, but I highly doubt that that was a design consideration. If stuff is expanding due to temperature change, it's not just moving in a perfectly horizontal plane making the shafts grow in length.

I don't see any big issue if it's mounted correctly, other than some vibration that will result if the yokes aren't on 100% level plane. Guys do just this kind of thing with rear engine drag rails to mount the tranny directly to the rear axle housing.

Hans

[-=AphiX=-]

Ya what he said

[Davethorik]

There has to be room for thermal expansion. It can chew up your u-joint or bearings in the transfer case otherwise.

I believe Jeep M715's have a stub shaft between the tranny and t-case that has no splines in it. How would this be any different?
As long as you have it mounted rigidly, perhaps a cage-type crossmember/skid that the whole mess bolts to.

[NOODLES]

to function properly, you need at least 2 u-joints, cause unless both are solid mounted, there will be side to side movements of the outputs will the mounts are flexing. if you can make that divorced t-case mount to the back of the trans and move with the twist of the trans, you can get away with running 1 u-joint, and a slip on one end, or even a bolt on yoke, with a u-joint and a flange. maybe make a solid crossmember with mounts for the back of the trans, and to fully support the t-case all one unit, then put the mounts on the outside of the crossmember near the frame mounts.