Does Hypoid gear oil SAE 90 = GL5?

[AR Huzgr]

I have a 2006 Yamaha f115. The manual calls for hypoid sae #90. 

 Does Hypoid=any GL5 rated gear oil?

What makes it confusing is yamalube has a HD (GL5) but says it is for the bigger motors.  The UD (GL4) shows as for the F115.

It makes it a bit unclear whether I should be using something that specifically says hypoid, or just go with the Yama lube UD which says GL4. 

 

 

[fishinwrench]

Hypoid lube is good for gear teeth....but "less good" for thrust bearings, thrust washers, and clutch dogs. 

OMC used to recommend hypoid lube for the old hydro-mechanical lower units (1968-72).....and as far as I know the only reason WHY was to quiet them down, because it certainly didn't improve the life of the shift components AT ALL.  

 

THESE are the shift dogs...

 

Whether you wear out the gear teeth OR the shift dogs.....you still have to replace the gears.   

Most gear wear issues are because of worn shift dogs, not because of worn gear teeth.

[AR Huzgr]

Thanks for the follow up fishinwrench.  

I suppose since the motor is 17 years old, the answer is go by what's on the current container, i.e., the UD GL4 rated, and don't worry about the term hypoid in the manual.  

[fishinwrench]

14 minutes ago, AR Huzgr said:

Thanks for the follow up fishinwrench.  

I suppose since the motor is 17 years old, the answer is go by what's on the current container, i.e., the UD GL4 rated, and don't worry about the term hypoid in the manual.  

If it were ME servicing that gearcase I would fill with one or the other of THESE...

 

I keep nothing else on hand.  And in my mind the only difference is the COLOR of it.   And it seems to me that the Evinrude (yellow) lube tends to lubricate better when a little water gets mixed with it.   The Mercury (blue) stuff doesn't appear to accept water intrusion at all.   Separates far more rapidly.   

[AR Huzgr]

Pictures worth 1000 words!   

Thanks much for your help