I ran my arbs with stock axels for a VERY short while, no damage but the splines appeared ever so slightly bent, took alot more hammering to get the longer side out than the short
-arb
-32" Maxxis MTs that bite
-lots of high traction slickrock out here
All I can say is if youre gonna wheel it on rock gardens and such, why wait to see if the OE stuff breaks? If youre gonna lock it up DL or ARB, my feeling is upgrade the axels. My diffs (OE )went 1st, and some of the wheeling out here is so remote feeling, coming from the eats coast, I rather upgrade to insure against a long hike or a feild fix, but thats just me.
Word has it you dont NEED to go HD axles with a TT- has ANYONE busted a OE axle shaft with a TT would be a better question, seems general concensus is if you lock=upgrade the axles.