Oil & Fuel Gear oil foaming

[Farwell]

I changed out the gear oil in my Troy-Bilt tiller. The manual calls for GL4 85W-140 gear oil for the transmission. I have not been able to locate any GL4. Everyone I have talked to at the dealer where I bought the tiller, NAPA auto supply and Ag equipment repair said to use GL5 85W-140 so I took their advice. I drained out the old lube and filled the transmission to the overflow hole as stated in the manual. I used the tiller for about 15 minutes, shut it off and let it set for around 10 minutes so it would cool off. I removed the plug in the over flow hole and real foamy oil came gushing out, there must have been a cup or more of the foamy stuff. I checked the container that the new oil came in and it said that it was an anti-foam type oil.
Anyone have this type of experience? If so what did you do about it?

 

[Rara Avis]

I changed out the gear oil in my Troy-Bilt tiller. The manual calls for GL4 85W-140 gear oil for the transmission. I have not been able to locate any GL4. Everyone I have talked to at the dealer where I bought the tiller, NAPA auto supply and Ag equipment repair said to use GL5 85W-140 so I took their advice. I drained out the old lube and filled the transmission to the overflow hole as stated in the manual. I used the tiller for about 15 minutes, shut it off and let it set for around 10 minutes so it would cool off. I removed the plug in the over flow hole and real foamy oil came gushing out, there must have been a cup or more of the foamy stuff. I checked the container that the new oil came in and it said that it was an anti-foam type oil.
Anyone have this type of experience? If so what did you do about it?

You can use this stuff...

Amazon.com: Royal Purple Max Gear Synthetic Gear Oil 85W140 1 Quart Bottle: Automotive

 

[Farwell]

You can use this stuff...

Amazon.com: Royal Purple Max Gear Synthetic Gear Oil 85W140 1 Quart Bottle: Automotive

Thanks Paul,
I will do some research on the Royal Purple Max. It sounds like it should do the trick if I find that I need to go that way.
Regular GL5 85W-140 should work because it is just a tiller and the stress, heat and pressure is not close to what a truck or car rear end would put out. I am going to give the GL5 another try before trying anything else.