LOCKTAB MAIN DOUBLE ROW BEARING HOUSING IN GEARBOX

The housing to retain the double row gearbox bearing has 4 bolt holes but the casing itself might only have 3 drilled holes where they deleted the susceptible to cracking hole on powerful engines. Originally 2 locktabs were used when four bolts, decreasing to one on 3 bolts and then on some gearboxes none at all.