Trailer troubles 99 trailer with a X2050 series astro on board

[Bubbabass1]

1999 21' astro on a 99 trailer tandem axles

The last two trips; one was about a 3 hour one way trip. No trouble on the way down, but on the way back had a blow out (front left). Lookng at the tire, it seemed to have two flat spots on it. Close to were it blew out. Makes me think the tire is locking up, but can't feel it while pulling.

2nd trip; 2 1/2 hour one way. All goes well. After backing into garage, wife notices the back right tire is bald and showing belts. Inner side of treads are worn completely down, with a couple flat spots on the treads all accross the tire. Makes me think the tire is locking up. But again, can't feel it while driving

While changing the tires i can spin the hubs and they spin freely.

Is it possible for the axles to be going bad? causing a tire to hiccup (lock for a second)?

Had new bearings and bearing buddies installed two years ago and bearings serviced last year while the fenders were being repaired.

Need some BBC wisdom

Thanks in advance
BB1

[375VTROCKET]

Very hard to say what would cause your problems but tires out of balance will cause flat spots, out of round tires will cause vibrations which may not be felt while pulling but will cause flat spots, inside wear can be caused by loose (to much play) bearings, bent/worn spindles cause inside wear.

It is really hard o say without doing some measuring and checking a lot of different things. But you will def. need some new tires.

[Bubbabass1]

Thanks rocket. A few more things to think about.
Out of round tires=flat spots
loose bearing= worn tires
bent spendle = worn tires
out of balance = flat spots

BB1