OOOPS, this may be late, i just noticed the date on the post. But, just in case here it is anyway. I would say that if you are checking them for high temp every stop it's very very unlikely you will have a major failure. I don't think they can "blow out". The first sign of falilure would be wheel wobble on the spline right? That would cause an elevated temperature which you would find at the next stop. Now, that don't mean you will be able to get on your way quickly. I broke a brake spring last time out and of curse felt it in reduced stopping power. A quick inspection revealed the problem, but finding the parts for repair took until I got home and then a couple days to get them shipped to me. But if you want to change them, I'm just guessing here but I bet someone at Dexter could provide the list of parts you would need to make the change over. Based on my recent experience it won't be cheap but all you would be looking for is a common wheel bearing set for an 8000 lb dexter axle. If you go to the dexter web site "home" and look under the "lititure" tab and you should be able to find them. As I recall they are listed by brake size. Mine (05 36 TK3) are 12.5 X 3.5. I think that's right. If not it's something close to that. Or here are two good contacts you can try:
jhoncharenko@dexteraxle.com (jackie is Customer service) or
Dbelisle@dexteraxle.com I (I think it's Duane but not sure, he is an engineer) both were very helpful to me just a couple weeks ago. Hope this helps.