theholycow wrote:bk7794 wrote:So I was doing more research on this topic. Apparently gear oil viscosity is much much different then normal motor oil.
API viscosity ratings for gear oils are not directly comparable with those for motor oil, and they are thinner than the figures suggest. For example, many modern gearboxes use a 75W90 gear oil, which is actually of equivalent viscosity to a 10W40 motor oil.Still a bit worried about changing the fluid.
Don't worry. Unless you drain or fill the wrong thing (a friend's brother drained the transmission and filled the engine) or forget to put the drain plug back in (a mechanic forgot to put the plug back in my mom's engine), the worst case scenario is that you spill the oil instead of catching it neatly.EDIT: Crap its actually 10w-30/40 listed for all year around. So what do I get? It also says 20w-40 or something for anything over 0 degrees.
We get close to (and below) 0°F enough that you should go with the all-weather recommendation rather than the "anything over 0" one.
I think I still will stick to the 10w, just to be safe.
Yeah I hear of jiffy lube doing that, scary thought if you think of it. Whatelse must just regular mechanics forget.
Well thats the thing, it has 10W30 on one side of the arrows, and 10w40 on the other side of the arrows. I might just do 10w-30. I will just get synthetic, that should be okay right. Even if there was conventional in there beforehand?