Not really a PSD-specific question but at least here's a place I know I can get a lot of TTB members in one place.

For those who know, I70 in the spring time is miserable. It seems to have claimed my front end. It makes a pretty decent clunking noise when I go over low-speed bumps, turn, brake or accelerate. It actually used to make this clunking noise when my front hubs were locked, but now it does it even unlocked.

I got under the truck and looked at the front end. 2 years ago I replaced all ball joints, u joints, pivot bushings, and steering components. Ball joints seem fine, steering is all tight. Here's where I noticed two things that caught my attention:

1. The axle shaft moves back and forth maybe 1/8 inch overall. meaning, if I grab the U-joints and pull it towards the wheel or towards the diff, it slides in its housing 1/8 inch. It does this on both sides.
2. When I jack up each wheel and wiggle/pry on the tires, they're tight except when I pull from 12 and 6 o'clock there's a SLIGHT wiggle. This typically means a ball joint is going out, but I saw no movement in the knuckle--it looks localized in the hub. I doubt it would be wheel bearing related, like a loose bearing or improper preload, because if that's the case wiggling from 9 and 3 would give the same feeling; this is exclusive to vertical wiggling.

Anyone have any insight? I can't really find too much info on this but if I were to guess, I'd say I have loose spindle nuts that have backed off to the cotter pins?

Thanks in advance!

 

You haven't changed i-beam pivot (TTB) bushings?

There's two of them and i recommend to upgrade polyurethane ones.

 

shoot sorry, yes I replaced pivot bushings as well. Just edited the post accordingly. So, it's interesting on that one. Sticking a bar in and prying does nothing. There's no weird movement, but the front most pivot bushing (diff carrier, driver side) actually isn't fully pressed in all the way--there's about a 3/32" gap between the shoulder of the bushing and the housing, but everything is all tight and no amount of prying can get that to move more than just flexing the rubber. I remember when I installed it that that bushing went in a little odd, and it seemed to have settled in some but no obvious clunk noise would originate from there. I may still just do poly ones eventually but something tells me the clunk is coming from axle shafts hitting retaining rings or the sort. I do not recall them wiggling like that before.

 

Take hubs off and measure spindles where the bearing rides with a caliper. Possible with loose bearing the spindles are out of round.
axles are floating and need to account for travel angles.

 

yeah once I get back to my shop I plan on taking the hubs off and checking. I can mic the spindle, but unfortunately I doubt there's any published dimension on what it SHOULD be. My guess is it's probably a pretty loose fit compared to the nominal bearing diameter, but it may have worn down too.

Another thought I had while thinking about this is the needle roller bearings on the backside of the spindle might be worn out. I find it hard to believe that the regular tapered bearings are worn out, as evidenced by my wheel wiggle test as well as the fact I replaced them only two years ago and 15k miles.

We shall see!

 

if a taper bearing locks up, the spindle will be damaged from the race spinning on it

mic it and check for roundness