Using GL-5 Gear Oil?

[Kensem]

Is GL-5 gear oil safe for replacing factory UDT oil in the front drive axle on my L3400?
Kubota mechanic told me to use 80w90 extreme pressure gear oil, but didn't say anything about the GL rating. I used some GL-5 in the transmission of my 51 antique jeep and the brass inside did not like it.
Thanks

 

[Sammy3700]

I may get corrected but I think you are good. It is a open differential so no need for anything special like limited slips require. Be sure to check the level after it sits overnight it takes the thick oil some time to run into all the bevel gears

 

[SidecarFlip]

I use 80-90 GL 7-8 in my front ends on the M's for shock load capabilities.

GL5 will discolor brass but won't hurt other than tarnish it.

 

[DaveMueller]

I believe it's actually the EP additives that attack brass. IDK if there's brass in the axle, but the only way to make sure the lube is OK is to contact the vendor. This is an endless debate on some other forums I'm on (old Jeeps) when the manufacturer calls for GL4 which is yellow metal safe.

 

[SidecarFlip]

I answered your question in post 3.

 

[thedevilyoulove]

I may get corrected but I think you are good. It is a open differential so no need for anything special like limited slips require. Be sure to check the level after it sits overnight it takes the thick oil some time to run into all the bevel gears

I found this out the hard way. I added 2 quarts of gear oil and it still didn't come out the lower hole. I went and got several more quarts from an auto parts store. The next morning, I pulled both plugs and a bunch of gear oil leaked out from the check hole (as it was supposed to do when the oil level is full).

 

[North Idaho Wolfman]

I wouldn't recommend the GL-5 stay with UDT.

Why do you think you need to change?