Sete ea gear e helical bakeng sa li-gearbox tse helical mechineng ea ho phahamisa ke karolo ea bohlokoa e netefatsang phetiso ea matla e boreleli le e sebetsang hantle. Moralo oa eona o ikhethang oa helical o fokotsa lerata le ho thothomela, o ntlafatsa ts'ebetso ka kakaretso. Boenjiniere bo nepahetseng ba sete ea gear bo nolofalletsa ho kenella ho se nang sekoli, bo fana ka bokhoni bo matla ba ho jara moroalo. E loketse lits'ebetso tse fapaneng tsa ho phahamisa, e tiisa ts'epo le ho tšoarella, e leng se etsang hore e be karolo ea bohlokoa ea mechini ea sejoale-joale ea ho phahamisa.
Likhamphani tse leshome tse holimo Chaena, e hlomelitsoe ka basebetsi ba 1200, e fumane liqapi tse 31 kaofela le litokelo tsa molao tse 9. Lisebelisoa tsa tlhahiso tse tsoetseng pele, lisebelisoa tsa ho phekola mocheso, lisebelisoa tsa tlhahlobo.