Help ID old Hurth transmission

[rossny]

I have a hurth trany problem. I remember seeing a sticker next to the atf fill bolt that has gone missing so I can't identify the model. So anybody know how to id ? The case on the port side has in the casting "HURTH made in Italy". and "38062 ARCO ITNI" the I's may be 1's. The existing sticker says ATF only. It's on a 1983 OM636 mercedes 43 hp in a 35' sailboat built in england. Thanks for any help....

[FPNC]

This can be a bit tricky but it looks like a Hurth HBW 100 nowadays called a ZF 10M.

[rossny]

Yes, thanks you are correct. It's an old 100 as I've just found the tag that fell off. Now trying to get the thing out. Rear motor mounts on the bell housing so have to jack and support engine as there is no apparent bolts to remove trans separate from bell housing......