ok then, so its different when the gears are beveled, still have yet to blow out the diff pinions or rings in my ofna, even when i lost throttle control and landed WOT, and thats WITH a jammin engine. my trick is to half fill the case with light silicone grease (sil-glyde auto grease), no problems with contamination and there isn't any drag issues either, but its messy when it comes time to replace diff oil.

spiral diff gears are still technically bevel gears