Lost a Wheel!

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Back on 5/6, heading up I-71 northbound from Louisville when I looked in the passenger's side mirror and saw a wheel bouncing down the shoulder. Thought perhaps I lost the spare, pulled over, and found I lost the right rear! No smoke; no heat on the axle. Have H-rated tires, did some calculations, and limped 2 miles to the next exit and a Walmart parking lot. This happened about 60 miles from home.

Threads on the spindle were toast so needed a new axle, plus new wheel/tire and disc brake parts. Axles/disc brake upgrade was done almost exactly a year ago. Only 5,000 miles on the set-up. Fast forward to yesterday (5/29). New axle and all parts collected and installer was available to do the repair. Dexter carries no axles in inventory (all made to order), but did expedite construction and I drove to Elkhart to pick it up.

Root cause of the issue: wrong outer bearing was supplied by Dexter as part of the disc brake kit and axles. How do we know? Other 3 wheels had play and the installed bearings were all wrong. Outer bearing supplied was a 48548 instead of the 02475 for the 8K axles. Outer diameters are similar so fit in the race Ok, but the inner diameter on the 48548 is a little larger for a different size spindle. That eventually allowed movement, then catastrophic failure. Only thing holding the wheel on at the end was the caliper which finally broke loose.

Few observations:
- was extremely lucky that the wheel came off clean and did no significant damage to the RV. The metal strip holding the fender was pulled off but that's it. The other tire was cut but did not lose air
- was extremely lucky that I only lost one wheel!
- was extremely lucky that the wheel stayed on the shoulder as it rolled/bounced down the incline. If it went into oncoming traffic, would have caused a major accident. Road was busy (around 4pm on Derby day). I went back the next day and actually found the wheel/tire which saved my TST sensor.
- there was no smoke or heat at that time which would have indicated a problem. Not sure when the bearing actually came apart.
- I am very happy that a definitive root cause was found and can feel better about towing in the future.
- If this was just a freak bearing failure, not sure how you would have prevented this unless you happened to catch heat build up or had jacked the RV up and checked the wheels for play. For awhile I may just jack the wheels every 1000 miles and check for play for peace of mind. And will continue to use my IR thermometer at stops.