I Wonder Why My Wheel Seal Blew?

You're right, it should be loose enough to remove by hand since I have to back it off 1/4 turn after all the endplay has been squeezed out. When I posted this, I still pretty hot about the situation.

Those threads are smashed flat. It's from tightening it while being crossthreaded no doubt. I'm thinking of trying to add a tang style lock washer right before the lock nut to help avoid this in the future. It would at least prevent the lock nut from backing off. Spicer doesn't show it on their fiche but I think it'll still fit.

 

I was going to retract my crossthreaded theory today actually. I agree with you and W923. I took a long thoughtful look at the smashed threads today and noticed something I missed yesterday.

The smashed threads are more smashed and less smashed in different areas surrounding the circumference of the inner nut. This certainly indicates the nut was spinning while simultaneously being crushed under the spindle as the endplay increased from gradual loosening. It simply wasn't tightened (or at least not to 300 lbs) when installed.

I picked up some locking rings to add in between the nuts and existing "locking ring" as an added measure of security. I hope it all fits on the spindle and leaves a few extra threads showing for good measure.

 

I'm going to look into a one piece nut setup tomorrow. Not sure if they make them for the older 402s. I checked Spicer's fiche and there is nothing showing there to lock the locknut down. I did manage to track down the tab style rings today and they barely fit on the spindle with the nut, locking washer and locknut all in place. Not sure why Eaton didn't do it this way but whatever...that locknut won't be backing off now that's for sure.

Just read up on those Stemco single nut deals that Skallagrime posted...I'm not impressed. Don't think I'll be going that route.