I wasn't sure exactly where to post this, probably shold be in drivetrain but was hoping someone who knows more about suspesions could give me thier input.
Within the last week i have developed a leak around the slip yoke on my rear driveshaft. With the 4" rancho suspension it pulled out maybe 1.5". rancho says you driveshaft modifications are needed but my seal obvisouly is having problems and i think its due to the yoke being pulled out. Its taken a year to happen. Anyone else had anything similar to this happen or am i just the unlucky one? Anyone think i should get a spacer from fabtech? i dont know how good of quality they are

 

Hey, are your Rancho blocks tapered? If not, add a shim to your leaf pack. The rear block sits at an angle, and longer blocks will actually move your axle backwards. My 5" RCD block extended my wheelbase by an inch!! I added a 4* shim and now mine is about perfect. 4 degrees would be too much for you....it will kill your driveshaft angle. I'd suggest 2 degrees. That will move your axle forward slightly as well as rotate your pinion forward and up. That should put you right about where you need to be. Much better solution that a driveshaft spacer.

 

Thanks for the input, but no my blocks are not tapered. How much do you think the blocks or shim would run? I called fabtech and talked to them about the spacer and it is supposed to ship monday.

 

If your blocks aren't tapered, then you need the shim. Add a shim on top of your Rancho block and you'll be fine. Shims are cheap, like less than $20. I got mine from Skyjacker.....but they only offer a 4 degree. There are 2 degree shims available...but I can't remember exactly where I found them. If you're interested, I can probably dig some up. They have to be for the 04+ F-150's. The universal style will not fit.

 

I just went ahead and ordered that spacer, thanks though!