What's missing?

[pdowling1]

I'd bet that trans is used on multiple machines & the extra holes are for mounting hardware in those other applications. Just a guess.

 

[MacTractor]

Those holes are used on my BX25 for the Flux Capacitor.

 

[rdsaustintx]

Too busy lusting after your vehicle lift to care much about that tractor. NICE shop!

 

[irvingj]

4shorts- curiouser and curiouser.... my GC2310 has the same threaded holes....

Ah! Must be for the non-existent plastic fan guard!!