Bonfiglioli specifies Shell Tivela S 320 or equivalent. They consider this gearbox to be "permanently lubricated" (hence no oil fill ports). 

They also design to a much different application with thousands of hours of running in a clean environment without regular dousing of sea water. Because heat is no issue for us and it needs to fit inside the mast, Amel removed the cooling fins, which you need to do if you replace it. Amel also used a different motor and drilled new mounting holes for it, and added delrin spacers.  

So, imho, the common sense recommendations on this db to add grease fittings and lubricate regularly with a high quality marine grease are what you should do. 

What are the conflicting recommendations have you gotten?

Why did yours crack? Are you fixing it or replacing it?

Cheers, Craig SN68 Sangaris

---In amelyachtowners@..., wrote :

Hi, Which is the manufacturer's recommended lub for the furling gear boxes and its thickness? my gearbox has cracked and I seep getting conflicting recommendations fro 'experts'.