HPI has an upgrade coming out for the Flux diffs that they are calling bullet proof - they look like the R & P from the CEN diffs that were being used to make diffs stronger. I see some are doing pre-orders. More about them here -
http://www.rc-monster.com/forum/showthread.php?t=23046
Unless that 1 1/2 gal is only a weeks worth of running, thats not shabby especially if you're jumping it a lot.