Gear oil question

[sgf]

I just bought a Takeuchi BT 015 mini excavator. The manual calls for GL 4 or GL 5 SAE 90 gear oil in the final drive. I can't find 90 wt. and I'm not inclined to experiment. Would 85w-90 work as well? I have searched on line and the few discussion on this, as to use in final drives tend to vary widely.

 

[foton]

yes 85-90 should be just fine the difference is gl-4 and gl-5 . gl- 4 is meant if a system has yellow metal in it as brass ,bronze ,copper. gl-5 is corrosive to those materials if it has a chlorinated formula, you would have to ask the manf. if they use this process. gl-5 has a higher friction resistance also. but both are usually fine in gear applications. Unless gl-5 is specified I use gl-4 because of it lack of corrosive potential . If you can find gl-4/gl-5 both rated oil it will have the good of gl-5 and the lack of corrosiveness of gl-4.

 

[sgf]

yes 85-90 should be just fine the difference is gl-4 and gl-5 . gl- 4 is meant if a system has yellow metal in it as brass ,bronze ,copper. gl-5 is corrosive to those materials if it has a chlorinated formula, you would have to ask the manf. if they use this process. gl-5 has a higher friction resistance also. but both are usually fine in gear applications. Unless gl-5 is specified I use gl-4 because of it lack of corrosive potential . If you can find gl-4/gl-5 both rated oil it will have the good of gl-5 and the lack of corrosiveness of gl-4.

Thanks, since the manual approves of gl 4 or 5 it probably isn't an issue but why not just play it safe with gl 4 as you mention. I was most concerned about the 85 being too light but I'll go with the sae 85-90 as you suggest.