Is it possible you don't have the axle spacer and/or the snap ring installed. Check this picture below.........see the groove in the axle (next to the brass bushing)? There should be a snap ring in the groove and a spacer between it and the brass bushing.



the snap ring is Toyota part #90520‑27023. There are actually 3 spacer sizes available. They are as follows:

90560‑27005 T=2.0, T=2.0
90560‑27010 T=1.8, T=1.8
90560‑27011 T=2.25, T=2.25

These are cheap (probably a couple bucks each), so personally I'd get one of each then go with the one that fits the best. Toyota says to put 22 lbs of outward force on the axle and select the spacer that fits the best.

There's more detail about this on page 4 of this thread: http://www.toyotavantech.com/forum/s...74-Wheel-noise