I have been told the exact same thing from our local Bobcat dealer, i spoke to their 743 expert and he said 10w30 or 10w40. I have been using Castrol RX Super for years in my 731, which uses the exact same pumps as the 743 series. This makes things easier if you use a diesel grade oil, as you use the same oil in the engine, and you can even use it in the truck you use to haul the Bobcat around with.While bobcat specs their own brand, their manual for my 93 753 said 10/30 motor oil as a substitute and for every loader of theirs I've had since. I'm certain this would apply to your 743 as well. Maybe 5/30 for winter use if you do alot of cold weather starts. If you can leave your machine indoors when temps reach -20 or lower that is recommended. If not let it idle for a 5 to 10 minutes before putting it to work. Btw I'm near fort frances. Ken
Thanks guys this really helps,I will be using same as my engine wich is 15/40 castrol GTX (GTX is now replacing RX Super). Now one more question, how do I go about to drain and replace my existing contaminated hydraulic oil? Please walk me slowly through it, pictures would be nice LOL. Thanks in advance DenisI have been told the exact same thing from our local Bobcat dealer, i spoke to their 743 expert and he said 10w30 or 10w40. I have been using Castrol RX Super for years in my 731, which uses the exact same pumps as the 743 series. This makes things easier if you use a diesel grade oil, as you use the same oil in the engine, and you can even use it in the truck you use to haul the Bobcat around with.
I do live in Australia, so the temperature doesn't get much below 5 degrees C. Like Ken said, on cold days, let the machine warm up before you start using it. The oil will be too thick when its really cold.
If the plumbing on the "B"series is the same as the standard one, they say to remove the hose from the outlet of the oil filter and drain the oil out of the hose you remove. Its really hard to get it ALL out, so if you are going to change your chain case oil i would drain as much as you can, then fill it up, run the machine a bit to get the new oil moving around. Then empety this oil into your chain case, repeat untill the case is full. I have done this on my old 731 to get the old "turbo oil" out of the system and replace it with RX Super.Thanks guys this really helps,I will be using same as my engine wich is 15/40 castrol GTX (GTX is now replacing RX Super). Now one more question, how do I go about to drain and replace my existing contaminated hydraulic oil? Please walk me slowly through it, pictures would be nice LOL. Thanks in advance Denis
I use hydraulic fluid called R & O from autozone. This is a good general purpose hyd fluid and doesn't break the bank on cost. I'm of the belief that it is more important for the fluid clean than expensive. Also when you drain the hyd fluid remove the small hose going into the bottom of the hyd tank under the back of the cab. This will get all of the fluid out of the tank in a hurry.If the plumbing on the "B"series is the same as the standard one, they say to remove the hose from the outlet of the oil filter and drain the oil out of the hose you remove. Its really hard to get it ALL out, so if you are going to change your chain case oil i would drain as much as you can, then fill it up, run the machine a bit to get the new oil moving around. Then empety this oil into your chain case, repeat untill the case is full. I have done this on my old 731 to get the old "turbo oil" out of the system and replace it with RX Super.
Good Luck!