What's your setup?
After going to 4S, the FLM diff cup failed on me. So I got the traxxas newer version they make, traxxas 6780:
Came with 1M in it, but I cleaned that out and put 500K in it. Was still too thick. But I found that my larger wheels/tires seem to be causing the truck to be pretty fragile anyway and I just switched back to 2.8 trenchers. Won't get through grass as good, but hopefully it will make it to the end of a bash day without blowing off shock towers, snapping arms and upper turnbuckles.
They sure look small though:
I have broken 2 of the MIP's in the past month. Likely partly due to the larger tires forcing things to bend further than reasonable, then the joint's in the cvd's bind and break stuff. Both times it was the male end of the cvd where the pin goes through it.
Prior to the tail end of last year and the 3-4 bash sessions of this year, I had been running 2.8 trenchers and in the 3 years up to then that I had MIP's, I only broke one of those like that... or at all. The fact that I broke 2 in a month on the front tells me I'm asking too much of it. Between the 4S power/speed and the large wheels, it just said "NO! DUMMY!"...