..... COMPLETELY TRUE... this is where i was headed with my line of questioning...
honestly i had pumkin toy figured for anything BUT a newbie, and the c- clip thing only breifly crossed my mind as something a newbie would do, but hey, i make stupid mistakes or over look things sometimes
very possible (considering how fast they broke after you got the new set)
missing c-clips on the input and counter shaft gears like "-Matt-" posted here--> http://board.marlincrawler.com/index.php?topic=78097.msg918917#msg918917
but if this was true, if you were going forward, the helical gears would cause the input to go towards the grill and the counter shaft towards the tailgate, am i Right? because i have seen on one occasion where the counter shaft has been pushed so far off the 63/32 bearing, it started milling away at the #2 housing and pushed the counter shaft cage bearing up against or (nearly up against) that ledge behind it but i believe (if my memory serve me right )the gears themselves were fine and practically untouched. i know for certain the small set of teeth on the counter were perfectly normal looking
this leads me believe it's more of an alignment issue, which is VERY rare in the RF1A Transfer Case, but helical gears by design can not take hardly any misalignment at all
so make sure both your dowl pins are there, not too deep...and TIGHT!!!... no wiggle wobble
also, as a side note, it's not a good idea to assemble a t-case with silicon. gaskets are a lot thicker than silicon (relatively speaking) and it CAN also create problems inside the case, like oiling and tolerance issues... and don't use both! just make sure the gasket surfaces are completely oil free, brake clean and a rag should do it. sometimes people will take the front of the reduction (or #1) housing to a belt sander to true up the gasket surface... there by causing the input and counter gears to get closer to the #2 housing, tightening the tolerance between the main shaft, and the back of the input... i have seen those two surfaces come into contact before so it's not impossible but something to watch out for....(this is probably not YOUR issue but its good common knowledge)
I had issues with a case in the past where a snap ring wasnt installed and one of the gearsets was slopping back and forth. no damage was eer caused to the gears. The case was getting worn down from the gear grinding against one of the bearing surface areas but it neveer caused any damage to the teeth or anything like that. I cant imagine that I have any alignment issues anywhere. Like i said noe of the housing areas have signs of gears slopping into them or rubbing together in places they shouldnt. I have built multiple cases with silicone instead of gaskets, we used to buld them like that all the time when my dad owned his shop. We have never encountered an issue with any of the other cases we have built, so i cant imagine that silicone rather than a gasket is causing my gears to explode. You can even see from the pics that the entire length of the broken gears is broken off. that tells me there are no alignment or gear mesh issues with the MC gears. I simply think its a product failure.
Also you asked about how my case is mounted under the truck. I'm assuming you are wondering about the t-case housing itself taking stress in strange areas and possibly causing the gears to deflect from one another and cause premature failure? I do have poly bushings at the framerails where the x-member bolts into place. its basically the same concept as the FROR x-member. I believe that if i was somehow having issues with the case taking strange stress from the mount, then the t-case housing would simply crack and split apart before it caused the gears to fail. I dont see how there could possibly be enough movement in the housing itself to allow the gears to deflect enough to break.
Also the back of the transmission is in perfect condition