Misc Has anyone shortened their rear driveshaft, and how much shorter is working for you?

[CJ27]

I want to use a longer Transmission and xfer case combo. I really like taking advantage of my CJ7 's great turning radius, so I prefer not to stretch the wheelbase any more than I would have to. I'm guessing some of you have done similar mods. I'm wondering how much shorter the rear driveshaft could be before it would cause more problems than losing some of my beloved turning radius.
Has anyone shortened their rear driveshaft because of modifications like a longer Transmission or Transfer Case ? Has anyone shortened one enough to cause any issues?

 

[CJ]

It is quite common to need to run a shorter rear drive shaft when swapping equipment in your CJ7 .
Just be sure you correctly set your drop and pinion angle.
Also be sure and use a double cardan shaft.
There are many places that will make one for you.
Tom Woods is highly recommended and they have great information on setting up your angles.

Custom Drive Shaft Shop | Tom Wood's Custom Drive Shafts

Trail Tested, Competition Proven, Show Quality Driveshafts and Slip Yoke Eliminators for Jeep Wranglers, Cherokees, Ford Broncos and more.

4xshaft.com

 

[TSB8C]

I did shorten mine when I installed the 700R4 auto Transmission , Novak adaptor, and Dana 300 Transfer Case . I needed to go about 3 inches shorter than stock, at 22.5" eye-to-eye. I also have a 4" suspension lift. So shorter drive shaft plus steeper angle = no bueno. So I installed a drop kit for the Transmission and Transfer Case - basically spacers that drop the skid plate down a bit from the frame. This angles the output of the transfer cases down a few degrees. I also had shims on the rear axle spring mounts to slightly angle the pinion upward, but custom ordered angled mounts welded when I got the new rear axle form ECGS. CJ is right with the recommendation of a double cardan shaft, but I didn't need one with my setup. I easily cruise 75mph on the highway with no vibration issues at all. If you're not familiar, here's a double cardan shaft (two u-joints at the left end in the pic).

 

[CJ27]

Thanks, that's very useful information. It will be a while before I can calculate all the new positions for everything, but I'm very glad to know that losing 3" of length could still work if I can get all the other angles right.

 

[TSB8C]