Gear Oil Mix and Match: GOOD IDEA OR BAD IDEA?

[Sharphooks]

I've always been pretty finicky about what the type of crankcase oil I use in my 4-strokes---stuck to Yamaha oil when running Yamahas, stick to Honda oil when running Hondas

What about gear oil? I've always jumped around, using whatever gear oil I had the most of at the time of the change-out

I'm getting ready for a long trip---I'll book major hours of run time on both my Hondas. I have a gallon of HPF XR (JOHNSON/EVINRUDE) --it's a synthetic gear oil manufactured for the new E-tec two strokes.

Using this gear oil in a 4-stroke Honda---good idea or bad idea???

thanks for the comments!

 

[trendsetter]

The evinrude gear oil would be fine to use in the honda gearcase. Just make sure you fully drain the gearcase and refill with the new oil. I wouldn't recommend topping up a gearcase with different oils.

As long as it's SAE 90 marine gear oil it will work in any gearcase that calls for that oil. Don't use non-marine grade 90w oil as marine grade holds water in suspension while the standard oils do not.

 

[Sharphooks]

Thanks for that, Trendsetter---yes, fully drained and replaced, not topped off. This stuff is very viscous---way more viscous then Yamalube gear oil.

Does not say SAE90 but it's definitely marine grade, manufactured for E-tec. Those are the ones that claim you can run them for 3 years without maintenance or worry...I'm hoping that's a good advertisement for their gear lube oil...

 

[scott craven]

sorry if this is off topic,

This thread has me wondering, I have some water intrusion into the lower unit
which has been ongoing for a couple years.
Had the lower unit press/vacuum tested, replaced the drive shaft seal, prop shaft seal was ok.
I change the gear lube 3 or 4 times a year
If I continue to use marine gear lube which holds water in suspension, is it doing much harm
to the gear box ?

 

[terrin]

Not sure if you have a gear shift mechanism seal but that water has to be coming in from somewhere.

 

[trendsetter]

sorry if this is off topic,

This thread has me wondering, I have some water intrusion into the lower unit
which has been ongoing for a couple years.
Had the lower unit press/vacuum tested, replaced the drive shaft seal, prop shaft seal was ok.
I change the gear lube 3 or 4 times a year
If I continue to use marine gear lube which holds water in suspension, is it doing much harm
to the gear box ?

What type of motor is it? It could be the seals behind the vent and fill screws. Those need to be replaced everytime you change the gear lube. They are one time use seals.

It's better that the oil holds the water in suspension because you still have some lubrication. Standard oil, the water would separate out and either the gears or the top bearing would be running in straight water and would fail.

 

[scott craven]

Honda BF50A
replace the vent and fill gaskets every time...( at $2 each)

 

[Enniberg]

I have been using Mercury High Performance gear oil for several years - have been told by several marine mechanics that is is very good. Even the Yamaha dealer that I usually gets my parts from told me that they will only use the Merc stuff, at least until Yamaha finally comes out with their own synthetic gear oil - this was a couple of years ago, so I guess this may already have happened.

 

[bigdogeh]

I have been using Mercury High Performance gear oil for several years - have been told by several marine mechanics that is is very good. Even the Yamaha dealer that I usually gets my parts from told me that they will only use the Merc stuff, at least until Yamaha finally comes out with their own synthetic gear oil - this was a couple of years ago, so I guess this may already have happened.

+1 on the mercury high performance gear oil. myself I wouldn't use anything other than that. just too many stresses (heat being one of them) being put on the modern lower units. I bought a 5 gal pail. worked out to about 8 bucks a quart. won't find it any cheaper than that. hopefully it'll last me for quite a few years.

 

[Fishbreath]

Plus two for Merc

 

[Island Fish Lifter]

Merc oil is probably the best if you put on huge hours between changes/ checks. I use normal 80w90, waaaay cheaper. I check it regularly and change it when necessary. I usually get my 100 hours on it anyway. Also, I use my judgement weather to change the plug gaskets or reuse. I get many oil changes out of one set of gaskets. Use your head, think outside the box. Always take what a salesman says with a grain of salt.