I have a 3" lift (installed this weekend and last night) and it looks pretty awesome. I'm excited to see the difference. I am rebuilding my driveshafts, but from what I've been reading, there is a significant issue with using a rotoflex rear driveshaft with the lift. I'm trying to keep things low cost, now, after adding up the bills for some of the part orders.

Questions to consider:

-Is this true or can I just be happy replacing the rotoflex and rebuilding the shaft?
-Do I need to replace the driveshaft with a different kind and put a 4 bolt flange on the rear diff?
-If I do put a 4 bolt flange on the back diff, what stock driveshaft should I get?
-Will I need a driveshaft spacer to counteract the greater radius of travel in the driveshaft?
-Would anyone be willing to share experience with this?

 

Personally I'd still go with the Rotoflex coupler. It's a 'suck it and see' scenario. Use the old one and nothing's lost if it breaks up. As far as 3" lift and additional radius, it's a simple trig calc, and at a rough guess it's negligible on the shaft spline slider section, probably just a few millimetres at most and certainly no worse than when you jack the stock truck up on the body and not the axle. Easy to check out though. Measure the height to the fender and check the shaft angle (use a 2' or 3' spirit level and known sized packers until level) and spline slider position measuring from the transfer box flange. Then jack up the body and set onto stands by +3" and re-measure to the fender top (equal to your first measurement +3") and then re-measure the shaft angle and re-measure the distance from the transfer box flange to the spline slider, I'll be amazed if it's grown more than plus 5mm absolute tops. Others may have different ideas but why waste your money if it checks out OK and you don't need to spend more hard earned cash.

PS - do all these checks and measurements on a flat and level garage floor otherwise any results are meaningless.

 

I do already have the rear drive shaft apart and could rebuild it with a new rotoflex (my old one is ancient and shredded). And the math would work out alright, but I bet there would be a bit more distance. I'll see if I can put together a diagram of the measurements.

 

It's not as much of a problem on D2 as it is on D1 for whatever reason. Maybe because d2 has radius arms and a watts link in the rear instead of just trailing arms and an a-arm.

 

Most likely you will wear out the rotoflex much faster with that lift. For about $180 you can get the drive shaft from L8. Will be better for off road use.

 

I couldn't find a $180 rear shaft from Lucky 8. theirs was $900! I'm still looking, though, because I don't want to buy a new rotoflex to just replace it a few months later. I might look at what parts are needed to do a conversion to a cardan or double cardan driveshaft, and if there is one that already exists that would do the job, see if I can buy it used, and rebuild it.

 

Here is a link to the entire kit.
Lucky8 Llc. - Take the road less traveled...

 

Also ask them for an extra spacer just in case yours does not have one. Mine didn't and was in a bind until Justin shipped me one.

 

Thanks! I will!

 

you can also convert it ti a standard u-jiont