Diff Pulley Fences Coming off on K1

[corsair]

After my race last weekend, I noticed on each of my ball diffs, one of the fence has popped off. This happens on the side where there is extra space in the bulkhead.

Thankfully, the belt has not slipped off the diff. Did this happen to any of you as well? When building these diffs, I already found the fences alot easier to put on vis-a-vis the SX3.