Gearbox Oil

[Justinde]

Hi All

Gearbox Oil- can I use anything? Can I use an Automotive Gearbox Oil/Auto Trans Oil? Is there an Automotive Equivalent? Inherantly, if its for ' marine use' its expensive- like wedding flowers so is there an equivalent suitable product?

 

[jason32038]

Re: Gearbox Oil

No Justin you can't use ATF. It's kind of like the stuff you'd find in a differential in a car or truck..not that you should use this type. It's more like a thin grease than a lube or fluid/oil. It has to be rated Marine for a reason.

 

[12vMan]

Re: Gearbox Oil

Marine gear oils operate in environments subject to water contamination. Most synthetic marine gear oils have designed qualities such as extreme pressure/anti-wear performance and resistance to foaming, even when subjected to 10% water contamination.
Will automotive gear oil work? The answer is..well, yes - with a risk...but ask yourself: what's it worth when you're XX miles from shore

 

[Frank Acampora]

Re: Gearbox Oil

Marine lowr unit oil is an extreme pressure oil very similar to automotive rear end oil, commonly known as "hypoid." It is named after the specially cut gears in the rear end of a rear wheel drive vehicle. The marine version does have more corrosion inhibitors.

I know a couple of guys that do use rear end oil--85-90 weight-- and don't have problems. However, they also don't have leaks either.

If you trust your lower unit to not leak at all, or if you intend to change lower unit oil frequently, then you can try saving money by using automotive rear end oil.

Personally, although I might use it, I can not in good conscience recommend it to others as it is not the manufacturer recommended product.