Synthetic 75w90 instead of SAE 90 in Yamaha...

[BullyT]

I've always used the recommended SAE 90 lube in the lower unit of my Yamaha F115 outboard. I really prefer to use synthetic oils/lubes, and was wondering if a 75w90 synthetic gear oil could be used in place of conventional SAE 90 gear oil?

 

[Realtech214]

lube is lube

 

[volk06]

Originally Posted By: Realtech214
lube is lube


Not all lube is created equally.

 

[oilboy123]

You need a marine lower unit gear lube. Do not use an automotive gear lube. It needs to be marine rated to be able to handle any moisture that might get into the gear lube.

 

[lyle]

To answer your original question, yes, any 75W-90 marine gear lube can be used in place of SAE 90 gear lube in your Yammy.

 

[gonefishing]

I use Amsoil in my Mercury: http://www.amsoil.com/shop/by-product/gear-lube/universal-synthetic-marine-gear-lube/

 

[doyall]

Originally Posted By: oilboy123
... It needs to be marine rated ...


Can you direct us to the 'marine rating' specs you speak of?

 

[BigCahuna]

Say your seal goes out on your outboards lower unit from fishing line, and it fills up with salt water. How would marine grade lower unit oil do anything differently then regular 90 wt gear oil, to provide any protection?.,,

 

[Bamaman1]

I prefer to change my lower unit lube very often instead of wasting money on synthetic lube.

You can buy a quart of Pennzoil marine lower unit lube for $5.60 @ WalMart in the sporting goods section, and one quart will do it for most lower units.

How cheap of insurance is that? Lower unit lube change is just a 20 minute job--tops.

Be sure to spring $7 for a pump style oil pump. It's the only way to get all the lube out of the bottle.