96 Country 4.0L mostly stock.

I have a bit of a bounce in the front tires or at least a noticeable vibration - occurs when above 60 mph. When turning slightly on freeway it becomes much less noticeable or just goes away. I have heavy duty Moog front coil springs (part # CC782). Also have 96 Jimmy rear leaf springs with shortest leaf removed - lift is about 1" net front and back - gross lift over what was removed is about 2" all around because of saging of the original stock springs. Just finished rebuilding the front end with the exception of 3 bushings that are still in place - left side upper control arm rear bushing and both the axle end of the upper control arms have not been changed - mainly because the originals looked pretty good. Fresh alignment and I checked the toe in and it looks to be spot on. Caster has not changed in 160K miles and maybe never - mostly because the shop I take it to is lazy. New tires on front and balanced twice.

Removed the front drive shaft - no difference. I inspected the front axle u joints. Left one was solid with no movement. The hub on that side is a Timken with 15K miles on it. Right one had a little play and I thought the u joint was bad. Pulled it today and find the u joint pretty good (amazing after 255k miles) but the fit of axle shaft to the hub was a little loose - that's where the play was coming from. This hub was changed out several years ago by a shop and I don't know what brand of hub was put in. Is that natural/acceptable or is that not right? I could pull the left one to compare but thought I'd start with the forum first.

Thanks in advance.
Larry

 

Is the hub nut on tight?

Once the hub nut is tightened to torque (185 ft lbs I believe), and the hub is attached to the knuckle, there should be no play in the shaft.

Plus, the splines on the hub fit the shaft tight, so there should be no wiggle room.

Maybe the hub itself (bearings) is getting loose.

 

Sounds like a axle shaft to me. (Cv axle?)