mk1+2 diff arms snapping?

[Talonmotorsport]

How often do the mounting arms on mk1+2 diffs break and what is it caused by? I know there is two notches in the casting which is where they go but does it only happen to cars that are used in anger such as drifting or where the engine power has been increased?

[MX-5 Lazza]

I've never heard of that!

[Eighteeteewhy]

Sounds dramatic.

[St. Anger]

Any pictures??

[Talonmotorsport]

If it is not a common problem while the diff is still in the MX5 I wonder if it is how it is mounted in the kit cars that are breaking them?

[Richyvrlimited]

It's only common on a crashed car.

the diff has - as you've noticed - a cutout to ensure it snaps in a safe area and absorbs some of a rear end impact.

If you're breaking them whilst driving around I'd, (wildly on my part), guess you have a mounting issue.