CSM19Z5M

I have a 2008 Wrangler Sahara 4dr that is stock. Last year, during my annual cross country road trip, I found two left rear wheel studs had sheared off upon my return. I had been pulling an empty M416 1/4 ton trailer back from Iowa. I replaced the studs and while doing so found the other three lug nuts tight. I chalked this up to the tire company that had rotated my tires right before the trip. They are suppose to torque the nuts but I suspected they used an impact wrench and had fractured the two studs while retightening that wheel. This year I had new tires put on it right before the trip by a different company and personally made sure they torqued the wheels correctly and then rechecked them when I got home. After logging 6,000 miles on the trip I found another stud on the same wheel hub missing. While removing the wheel to replace the stud I found another nut that was about to fall off due to a sheared stud! What the heck! This cannot be a coincidence and I investigated as I replaced the two studs. I found that of the two bolts sheared off, one was a replacement from last year that had sheared and the other was adjacent to it and an original. I again this year had been pulling my M416 with a small light load in it. I cannot see any distortion in the wheel mating face or holes and the contact it makes with the hub seems uniform. There is no observable runout in the hub either. But clearly, something is not right here. Why the same hub? The shearing always seems to be two adjacent studs too. I always cross torque the nuts as spec'd. I drive primarily on highways and no off roading except for occasional gravel roads. Has anyone ever had this problem or have any ideas on cause? The Jeep dealer is clueless too.

corupt1

Running stock tires and wheels? If running aftermarket, are you using wheel spacers?

CSM19Z5M

bEverything is stock. I've had lots of off-road type rigs in the past including Jeeps and have never had a problem with lug nuts or studs. I've had hot rods with all types of wheels and tires and driven them very hard and never had stud problems. I thought that maybe the nuts were causing the problem but it should be happening on the other wheels too if that were the case. I know the threads loosen up after they have been spun on and off a few times. The studs always break almost flush with the face of the lug nut versus closer to the hub. Most of the advice I have been given so far has been directed at the way the nuts are tightened but over tightening / under tightening was not the cause this time. The tires have been rotated and also replaced so the wheels have been moved from one axle to another so that seems to rule out a bad wheel. It is weird.