Vibration diagnostics

No. Replaced steer tires and alignment in November. Tires wore perfectly. Changed drive tires at the end of March, vibration started in April. After vibration started bad wear on driver side steer appeared. Very inconsistent wear. Smooth nearly hallway around the tire then like 6 inch chunks that aren't wearing with bad wear between them

 

Still trying to figure this out...

Forgot to mention that i went to the house directly after replacing drive tires that time. Before i left the house my truck with empty tank trailer had been towed from where i had it parked. Tow company claimed they dropped the drive line to tow but i couldn't find any signs of this on the u joint bolts. I don't know how it could be involved but i hadn't noticed the vibration start until after this happened.

Recap of what I've tried so far. I've had the front end checked multiple times with nothing indicating any significant enough signs of problems to need to replace anything, King pins feel tight and all of that. I've had all tractor tires machine balanced, bad rim on steer should have shown up here but no indication of that. I've replaced all 5 u joints and carrier bearing along with steer tires at one point. The vibration all but went away for a while after that. It ultimately came back being most prominent around 40 to 45mph. That set of steer tires didn't last but about 9 months so i didn't see the weird wear on driver side steer. I also have replaced all brake drums and hardware along with replacing steer wheel bearings and shocks, that had no effect. I had to replace the steer tires with used tires after the ps steer went down. That same weird wear pattern came back on the driver side with current tires. First tires when i first noticed vibration were Michelin, other 2 sets i had to use Firestone. I don't think it's the tire specifically because of this. The wear is very weird and I've never been able to find any information about this specific wear, not able to find anyone (tire professional or anyone) that had seen this unique wear.

The outer edge of the shoulder is wearing faster then the rest of the tire. About half to 2/3 of the circumference of the shoulder is just normal but excessive wear. The other part appears to have cupping like wear. I would expect the cupping wear to go the full circumference but it does not.

I've had suspicions of the leaf springs since the beginning but couldn't see how they would cause this and didn't have justifiable reason to change them. Developed clunking and banging recently and now have new springs and shackle bushings I'll be replacing in a couple days. Also planning to replace steer wheels altogether, going to get the 9"rim for the 315 tire. Planning to have 3 axle alignment after replacing wheels when i can afford to do so. Sure do hope the springs have been the culprit all along.

Don't know if anyone reading this happens to have the recommended procedure for replacing the springs. I could definitely use a few pointers and the torque specs. I've not really been able to find any of this online.

Thank you for all who read this, hopefully we can figure this out ultimately and the next guy going broke trying to figure a thing like this out will be able to save some money

 

Finally remembered to take a picture of how there's cupping wear on only about 1/3 of the outside edge of the ds steer, some excessive wear on all of that outside shoulder. This has come through like this on 3 tires in a row, first Micheline then 2 different firestones. Finally shackle bushings started to go so i replaced them and completely replaced springs. Looks like the ds spring was getting weak and sits just a little flatter. Shocks surprised me, still have a lot of resistance in them.
After changing springs i changed wheels on steer completely, 9"rims so i can run the 315. Balanced on a machine, reputable shop. Had 3 axle Lazer alignment also. Checked all components, looked good. I watched as they pried on tire, ps no discernable movement whatsoever with King pins, ds might have moved a 64th if that. Steering has always been good and tight, all components appear good. Adjusted steer axle toe from -.25 to ,05. Added about 3/32 on ds rear drive and took off 1/32 ps front drive to correct thrust.
Vibration remains.

Got to playing with ride height again today, think i might have made a little progress. Hopefully fiddling with it might make cure.

No clue if it's the right story but my thoughts are trending to this. Tow company that took off with my truck for being parked on private property (had been parking there for a year with no response from owner or reason for concern) must have taken drive line off like they said. Maybe they lost a spacer for carrier bearing or damaged it. Truck was towed right before vibration started, haven't understood how it could be cause but might be getting it now. Probably lost a spacer for carrier bearing. Since i just replaced all drive tires i started suspecting them on this adventure. Leveling valve was replaced and ride height might have gotten set wrong because of missing carrier spacer. Carrier was also wearing out due to vibration from wrong angles. Vibration was significantly reduced, all but gone after i changed 5 u joints and the carrier bearing but it came back. Ride height is probably still wrong.

Going to try playing with ride height and figure out if i can find what my exact measurements are supposed to be with drive-line angles and tranny and rear ends. If i can get the correct angles and my crooked eyes and measure right then I'm guessing I'll discover I'm missing a spacer for the carrier bearing and hopefully cure this dadgum vibration gremlin once and for all!

 

Back home running local to Casper wyoming. Not many shops around here...