Any axle boot without a shield is gonna shite the bed eventually. The pre 5t SC/5B 2.0 carriers are just an axle boot death waiting to happen if you're running anything larger than the stock drives, which you are. That's why I went with the FLM carriers. They don't envelop the boots, so they can expand without any worry of snagging on the carrier. With my crappy pyrex lid shields in place, the carrier boots have held up for the longest I've ever seen. 10 runs so far, and no sign of stopping. One is even an old non-SD stock HPI boot! ? . Can't say the same for the transmission sides; I lost one side in a short run at the rocky park. The other is still holding up, but another run on the rocks might change that. If hostile boots ever get restocked, I might build in a secondary shield to protect them. For now, I just have extra FLM drive pins for the bones and will track the wear that happens on the un-booted drive cup.
I'm considering going the route of the Godzilla drives and just pressure fitting a copper or bronze ring around each cup to keep it from throwing the drive pins and running without any kind of boot.
Think about it, the Losi models aren't running boots out of the box, and they're just fine. It made a lot more sense when the drives were smaller and more prone to breakage. The large scale hobby has come a long way since then.
I think you should experiment with whatever you want and see if something eventually works.
I am extremely worried about your spur gear situation. If you're melting plastic gears, steel won't do you any favors if there's something fundamentally wrong. Case in point:
This was due to a pinion that wasn't fully seated on the bell. It walked back and forth and shredded the spur.
I've been running the stock plastic spur without a cover for the last few runs now, and it's looking nothing like your Hostile: In fact, it still looks brand new. Either Hostile's plastic is completely garbage, or you still have a mesh issue.
After seeing Enzo's
thread, I get the feeling that the last gen Hostile spurs just aren't up to snuff anymore. But you should still try running the stock gearing if you can just to see if the spur holds up before investing in steel gears.