3 driveshafts broke in 1 week.... I'm stumped...

or built a trac bar for the rear so no more axle wrap...anyway it will help if its the problem or not

 

x-2 on the above..

 

Good info on drivelines here. You need an anti-wrap bar like the one in this picture. Notice how the front mounting location uses a "shackle" like design. This design keeps the axle tube from twisting.

 

another thing just to complete what pielut said, shakkle is there to help while the axle flex...the big problem on the setup show on the picture that type is use for road only because i doesn't give you any flex possibility. Best thing to use is 3 rod end so i could flex easily...

 

Here's the wrap bar I made. The shackle mount on the end is a threaded rod-end, screwed into a welded-in bung. It allows the bar to pivot when the axle articulates. I know there is some tension on the springs when they are compressed or extended, but nothing that really seems to inhibit their movement.


Instead of welding the bracket directly to the axle housing, I welded it to a section of Schedule 80 pipe that just fits over the axle. This allows you to make your welds to the axle along a horizontal axis rather than a vertical. Vertical welding on these small tubes weakens them and is a sure bet to cause problems later. Can you say cracked axle tube?

 

To add to what Posimoto said, the only end that needs to pivot is the shackle end. I'd recommend rubber or poly bushings on the axle housing end for some give, but the shackle end is the one that needs to twist. Whether it's a threaded style like he has, a full free float twist affair, one with a spring, or a Rod End.

 

I used YJ spring bushings, cut down, for the bracket ends of the arm.

 

I have the shackle set up with yj bushing's on the axle and the shackle.
No pivot points.
This is with the mono leaf jeepster setup, spring over, and works really well lots of articulation.
It also really plants the axle on acceleration.

 

It seems to me that it would wrap up more in 2wd .. At least mine always did. He says as soon as its in 4 lo it breaks it. Sounds like a transfer case in 2 different ranges or something crazy like that. OP stated he was hammering on it when it broke the first time. Now evary time he puts it in 4lo.. Its fine in 2wd. Could the transfer case be in 4hi in the front and 4 lo in the rear ??? I dont know much about the model 20....

 

Seems like that would destroy the t-case, not the driveshaft. If it was fine before the first break I would have to say something else happened when the first shaft broke that hasn't been addressed. Spring pads broken loose from axles? If it's just breaking driveshafts and not spitting the u-joints I'd have to say the fault is in the driveshafts themselves. If it's spitting out u-joints then it's got to be wrap or broken welds on the spring pads or some combination of those.