Pete air-trac issues

U bolts need to be re torqued after initial torque. Could be the issue. Usually a few weeks after install.

 

Then you have something worn. Maybe the bottom of the axle housing has worn. That can be welded and ground pretty close to stock. Good idea by replacing the saddle. Make sure your using genuine pete parts because the ubolt nuts are special. If nothing is worn and it still comes loose, I have nothing for you =P
I've seen that aluminum lower saddle wear into the axle tube several times.

 

Try Thread lock, double nuts using a thinner nut for the locking nut. Mine never came loose.

 

Be carefull.
Some axles cannot be welded because they crack just beside the weld.
Has to do with the thickness off the axle.
Don't know about yours.

 

Once ubolts come loose and the saddles start to bang around they can lose their flat/smooth edges and surfaces. Once they are bolted back up again, the mating surfaces between the axle housing and saddles and the spring itself never wants to sit flush. If anything has any angles or irregular wear you will need to replace those parts. Always use new ubolts and use an actual torque wrench on them.

 

Are you using new u-bolts?