2001 4runner, stock, 180K. Rear driveshaft new factory part. New Rack, poly rack bushings, new Billstein's (all 4), front drive shaft is perfect (very little use), Tires are lug centric balanced on a road force machine, new alignment.

OK now that I got that out of the way, I have the damn 60-70 mph vibration. it is the worst at 68mph. I did find where the CV axle goes into the front Diff, on the drivers side, to be ALOT more loose while pushing it up and down, not in and out. I have heard that this could be a differential bearing issue or a CV axle issue. The seal on the front diff on the drivers side is not leaking at all. This tells me that it is not the bearing in the diff.

Please pose your opinions. Thanks in advance!!

 

It could be a couple things, even unrelated to the cv axle. Have you checked for tire play? Jack each front tire up and check for wobble. Any side to side play can be your inner tie rod. If you have ANY up and down play, even a little, your wheel bearing is going back and probably needs to be replaced soon (which btw, is a serious pain in the butt job). Seeing that you have as many miles as you do, I'd say it's time to freshen up with new ball joints, tie rods, and bushings if you haven't already.