what kind of gear oil is best for a 25 hp jonhson J25tecrd i mostly use if for duck hunting, is some better for cold weather, what brands are best ect does the oil need to be mached to the load on the motor
For that motor, go to walmart and get any outboard lower unit lube. Any lower unit lube will work in that outboard- nothing special needed. Even in colder weather.
Your dealer can provide you OEM product as well- but it isn't necessary in your application. More importantly is how often you change it and keeping up on the maintenance of it.
I personally use Valvoline EP90 gear oil - just ordinary stuff you'd put in your gearbox / diff. Heaps cheaper than 'marine grade' oil. Ziemann's right, just change it every season / 50 hrs or so.
Really anything that says "lower unit oil" is fine.
You should change that fairly often anyhow to keep an eye on your lower, I do mine twice a year and check in between just to be sure no water is getting in and I use what ever they have at Wal-Mart.
This oli is pretty inexpensive, even the good stuff. I used to use the Penzoil Marine lower unit oil - GL-5 rated. Wallyworld has it for about $5.00 a 32 oz bottle.
Last time I did mine I bought the quicksilver premium lube - no GL-5 on the bottle but it says rated for all outboard lower units. It cost $8.00 - they were out of the penzoil stuff. The first thing I noticed when I opened the bottle was long strings of oil would come out when you touched the oil and pulled your finger away.
This lube will clearly pull around the gears better then the Penzoil which is like thick dino oil. For the extra $3.00 I'm sticking with it.
