This is the same problem I am having. Anyone know how to resolve this?

I got the same thing from a 2" OME lift! Nothing seemed to work so I finally swiched to a double-cardan joint in the front of the driveshaft and wedged the rear 6 degrees up to get almost 0 degrees of angle on the rear u-joint. It's still a little bit low in the rear pinion but the vibration is 90% gone.

4Crawler, what would a set of 7 degree wedges go for, shipped to 98226? I'm still running the aluminum Pro-Comp wedges I bought to get the angle right. I think I paid $18 a pair for a set of 2, 4 and 6 degree shims.

Thanks.

In steel, see below:
- http://www.4crawler.com/4x4/ForSale/Shims.shtml#StdWidthShim

I guess 7 degree shims might be what I need as well. Have a set of 6 degree shims on there and still getting a little vibration.

BEWARE THE SUPERLIFT SPRINGS FOR OLD 4RUNNERS! THE 3 DEGREE SHIMS THEY COME WITH DO NOT WORK FOR THIS APPLICATION!

I have changed everything in the rear end trying to get this right. New ring and pinion, Trutrac, D-shaft, U-joints, shims. Finally pretty close after a lot of pain and $$$.

That is typically the case, since the spring maker can't know ahead of time what vehicle the springs will be going on. Since those would fit on a 4Runner or SWB pickup or they could also go on a long bed or Xcab pickup with a 2-piece driveshaft and center CV joint.

Best option is to measure your drives haft angles *prior* to lifting it (that way you know where you started and and what worked) and then measure afterward and see what changed:
http://www.4crawler.com/4x4/CheapTricks/Driveline-101.shtml#Single-Cardan-Measurements

And then if you have vibration issues, you'll know what needs to be fixed.

Thanks Roger. Although it's a bit too late for that. Wish I would have known. Do you have any idea what the stock angle is for a 1988 Toyota 4runner with a 3.0 and auto trans? It is running pretty good now but with a little vibration at 55+ when I let off the gas. This is with 6 degree shims. Do you think 7 degrees would be enough? How long would it take to get a set from you? Thanks again.

Easy enough to measure the angles you have now and see how far off they are. See the web page above for how to do that.

I have to ask, since I don't feel like reading all of that.
did you replace the U joints?
they can still be tight, but have a area worn, if they are old. now that you have changed the angle of the drive line they can be (jumping up over the worn area's) and causing a vib. I have lifed many high milage trucks and it only took a few before I started replacing the (tight) u joints for new ones and the problems went away. some of the u joints that (felt) good, when you took them apart (some) you could see and feel the old worn area's. some you could not. I tried some of the ones that you could not... and the bearing would eat them selves in oh... 500 to 2000 miles.

just a thought.

Both U-joints have been replaced. The front close to when the springs were put on and the rear I just did the other day. Now I am wondering if the bearings were damaged between that time. Only makes the sound when I let off the gas at 55+ and is much better since I replaced the rear U-joint. Thanks for the input.

The vibration may be due to a worn out slip yoke or loose pinion bearing. If those are both tight, then you may have the pinion angle too low. Why? Pinion tips up under load and thus runs smooth. When you back off the gas, the pinion drops, increasing the angle and possibly causing the vibes.