Optional fluid for transmission and transfer case????

[lcp]

From good sources on this forum, I've learned that our manual transmissions and transfer cases require a GL-4 gear oil due to yellow metals used internally. I've found 2 good options: Amsoil Synthetic Manual Transmission & Transaxle Gear Lube and RED LINE MTL® 75W80 GL-4 GEAR OIL. I also own a Jeep TJ with an AX-15 manual 5 speed transmission that calls for GL-4. Quite a few technicians, even at dealerships, apparently recommend using a synthetic 10W-30 motor oil in the AX-15. Could this be a viable alternative to the GL-4 in our Roxors???

 

[lcp]

@lcp: I would not go to far off the spec in the user manual. Maybe a lighter (75/80) weight if your in cold climate year round. Maybe go heavier (85/90) if you're in warm-hot climate year round.
Since you are in Texas and mostly war-hot temperatures, you might use a single weight Gl-4. For instance a gl4 90. Some farm stores have a gl4 90 instead of a multi weight such as 85/90.
If you go to Amazon you can get a gl4 85/90 Sta Lube for $52 per gallon (Napa does have that brand, too). Pricey? Sure. But that's an expense for only every few years.

I see your point. Thanks for the input and the recommended 3rd option.

 

[lcp]

Just get what's available in a gl4 in the weight range the manual recommends.

I used a gl4 by company "Driven" in transmission and transfer case in my two machines. Summit Racing and others carry that brand.

In my 1950s Willys, I use the gl4 by Sta Lube brand.

The nice thing about Amasoil is the oil comes in a pouche and you don't need ro use a pump.

One more thing: get an 8mm square drain plug wrench for $6.99. Its either the transfer case or tranny that has that size plug.

I'm attaching some info I found on 5 options, a couple are thanks to you. Thanks again.

 

[txroadkill]

This is what I’m running in mine. PennGrade Multipurpose Classic GL-4 Gear Oil - Free Shipping on Orders Over $99 at Summit Racing

Unfortunately I couldn’t find any gl-4 locally so I resorted to ordering it and doing so in enough quantity to always have some on hand if I was ever to need it for top off or a complete change.

 

[lcp]

This is what I’m running in mine. PennGrade Multipurpose Classic GL-4 Gear Oil - Free Shipping on Orders Over $99 at Summit Racing

Unfortunately I couldn’t find any gl-4 locally so I resorted to ordering it and doing so in enough quantity to always have some on hand if I was ever to need it for top off or a complete change.

I couldn't find it locally either, so I ended up ordering the Red Line MTL from Amazon. It was supposed to be delivered on Monday the 28th, so I drained the tranny and transfer case that morning. It actually showed up on Wednesday and was missing a quart. I spent half the day trying to figure out how to get that missing quart to me so I could use the Roxor this weekend to show visiting family members around our place. The best Amazon could think to do was refund my purchase and direct me to reorder the oil. It should be here on Monday the 4th. Apparently, a short apology for the minor inconvenience and overnighting 1 quart of oil to me wasn't an option.

I learned 2 things here: 1) it's nice to have options to choose from, and 2) Amazon's customer service sucks

 

[txroadkill]

Did you have to send back the oil they sent already?

 

[lcp]

Did you have to send back the oil they sent already?

No. I filled the transmission and put roughly a quart in the transfer case. When the rest of the oil comes in on Monday, I'll finish filling the transfer case and call it good. They refunded the original purchase, so I basically got 3 quarts free and only had to waste half a day dealing with Amazon's phone representatives and wait a few more days to finish what should have been done last Monday.

Just to add to the info in this thread, I'm attaching the PDF info sheet on the PennGrade oil.

 

[RPD-Nick]

In the 2018-2022 they call out GL-4. In 2023-2024 it went to GL-5 which also still covers the GL-4 spec.
If anyone needs it we stock it. Below is a link.

80W-90 EP MAHINDRA GEAR OIL SAE GL-5​

 

[motormd]

AMSOIL GL-4