Driveshaft spline movement - How much slip is actually needed?

[Tito]

On the rear driveshaft, how much actual spline slip is needed since the shackles technically move the axle fore and aft as the suspension cycles?

 

[Madgyver]

3.5" - 4" should be ok with 1.5" out at ride height..
With your short and steep angle it may be alot different...

If you're getting the shaft built then I'd ask from more slip...

 

[Tito]

I guess with a shorter shaft you get more movement. My previous shaft was 49" long and never moved more that an inch either way so a total of 2" of movement is all I ever saw (and I did look).

 

[ugly74]

to be sure, you'd need to measure how short the shaft would be when the suspension is absolutely compressed, and then measure how long it is when the suspension is not holding any weight at all. take the difference between the two, add a couple inches at each end for good measure, and then get a shaft that can slip that far.
honestly, though I'm just guessing. that's my plan for when I get a lift big and flexy enough to hafta worry about it.

 

[SpareParts]

Mine does not move very much. With the doubler, I was kinda concerned about my front, it doesn't have much room to colapse but I have flexed it out on the lift several times and with the 7 days of trail rides I haven't had any problem.

David

 

[Tito]

Mine does not move very much. With the doubler, I was kinda concerned about my front, it doesn't have much room to colapse but I have flexed it out on the lift several times and with the 7 days of trail rides I haven't had any problem.

David

That is kinda what I was figuring. Last time I talked to Tom Woods he said the large slip[ joints in the rear are pretty much unnecessary while still using the shackles since the axle moves in and out as the it articulates. The front is where it is really needed.

 

[SpareParts]

I think with the long arms and the doubler the front doesn't move as much either, my radius arms pivot the same as my driveshaft does. There for they move in the same arc and the length don't change. Maybe ??

David