Eaton posi trac and diff fluid

[dailydriver]

Maybe try what Brian has suggested; adding in 6 ounces of the XL-3 initially, and then add the other 2 ounces from the second bottle if and only if it still chatters after doing the figure 8s.

If it still chatters after adding 8 ounces of the strongest limited slip FM available (the Motorcraft XL-3), then yes, something else is wrong, and it needs to be returned to, and warrantied by Eaton.

 

[BlueBird]

All of the synthetics we tried did not work. Mineral 80w-90 is the only fluid that stops the chattering.
I taked with the Eaton tech this morning. He's conviced that its the quality of gear oil that im using that is the problem. Apparently Valvoline and MotorCraft 80w-90 are not up to spec for the Eaton unit. Mobil1 sys should have worked , but it didn't. They originaly speced mineral oil but now the trend is to recommend syn but for me they recommend I try Shell Spirax HD. I think that's the mineral oil.
Anyway, I could send my Eaton unit back for inspection but that would require pulling the unit and the truck would be laid up 2 weeks or longer.
So, I guess ill try the Spirax soon and see how long that lasts.

I wouldn't recommend a posi Eaton unit to anybody wanting a posi.

 

[Ken2]

Quote:
He's conviced that its the quality of gear oil that im using that is the problem. Apparently Valvoline and MotorCraft 80w-90 are not up to spec for the Eaton unit.
This makes no sense. The specs have been established for many years. Valvoline makes top quality products, and if Motorcraft buys their gear oil from ConocoPhillips like they buy motor oil, then this is another top quality product.

Show me any top brand GL-5 gear oil that does not meet these specs:
"Shell Spirax® HD oils are high performance multigrade extreme-pressure, multipurpose gear lubricants. They are suitable for heavy-duty truck and automotive differentials, manual transmissions and oil lubricated wheel bearings. drive-train gears of heavy-duty automotive, trucking and off-road equipment operated under high-speed/shock load, high-speed/low torque and low-speed/high torque conditions. They meet the requirements of API GL-5 and MIL-PRF-2105E and are available in two SAE viscosity grades: 80W-90 and 85W-140.

"Approvals and Recommendations
• API Service GL-5 and MT-1
• Mack GO-J, GO-H, GO-G
• MIL-PRF-2105E, SAE J2360
• Meritor Automotive, Inc (formerly Rockwell) O-76-A (SAE 85W-140) and O-76-D (SAE 80W-90)
• International Truck and Engine CEMS B-22

"Note: cars equipped with limited-slip differentials may require a different lubricant specified by the manufacturer, such as Shell Spirax® LS."
http://www.mil-specproducts.com/Documents/547_PDS-SPIRAX HD 80W90.pdf

I think there is something wrong in your unit.

 

[dailydriver]

Originally Posted By: BlueBird
All of the synthetics we tried did not work. Mineral 80w-90 is the only fluid that stops the chattering.
I taked with the Eaton tech this morning. He's conviced that its the quality of gear oil that im using that is the problem. Apparently Valvoline and MotorCraft 80w-90 are not up to spec for the Eaton unit. Mobil1 sys should have worked , but it didn't. They originaly speced mineral oil but now the trend is to recommend syn but for me they recommend I try Shell Spirax HD. I think that's the mineral oil.
Anyway, I could send my Eaton unit back for inspection but that would require pulling the unit and the truck would be laid up 2 weeks or longer.
So, I guess ill try the Spirax soon and see how long that lasts.

I wouldn't recommend a posi Eaton unit to anybody wanting a posi.


That Spirax IS a mineral based gear oil.

One more you could try, but expect to pay synthetic-like prices for it, is the Lakewood BFL 80W-90, mineral based gear oil.
(I have NO clue who makes this stuff for them.)

I've used this way back when this diff was new, and with the XL-3 additive, and properly set up 4.10 AAM gears, it was dead quiet with NO chatter, or gear whine at all.