Mowing Mower Gearbox Oil

[rock]

Last leaf pickup yesterday, took the mower off the BX and figure it has around 90 hours on it. According to the manual I should change the gear box oil and use SAE 90 API GL5 gear oil. I've got a bottle of 80W 90 gear oil that is API GL5 rated. Is that the same stuff or should I go in search of straight SAE 90 gear oil?

Thanks in advance...

 

[gobbler]

Pretty much the same stuff. I used 80W90 in my mower gearbox.

Jim

 

[AZMike]

I agree. I have used the 80-90w gear oil too with no problems.

 

[JohnMiller3]

Most gearboxes are very forgiving and tolerances not quite that of an engine…

Some VISCOSITY similarities between engine oil and gearbox oil: (to give you a better idea)

Gear …. Engine
75w ~~ 10/15w
80w ~~ 20w
85w ~~ 30/40
90w ~~ 40/50/&Beyond

So all in all, I don't think you'd have a problem, but to be sure, check with the mower mfr...