Maybe look out for some 85w140 gear oil, or ask anyone doing oil changes, if its used oil from a vehicle differential thats ok as long as its still pretty clean, filter it through cloth, it takes some time, or let it stand in clear containers and it will settle, pour the clean off the top(its a long wait process, stack them away in your shed) thiese hypoid gear oils will help in bar life 50/50 with your 150weight chain and bar oil