Rear Axel

[Deleted User]

I can't find straight SAE 90 weight gear lubricant for the rear axel in my 52 Hornet. Is SAE 80-90 weight the lubricant of chioce these days for this application?

[Deleted User]

You can find good ol' fashioned 90 wt at Tractor Supply.



Just last night I was talking to Rudy Bennett on the phone about this very subject. He had a conversation with the lubrication engineers at Caterpillar about how thin (like the rest of us think is not sufficient) the gear oil was.



The way they described it, it has superior lubricity to the older grades and actually dissipates heat much better than the thicker types of the same grade. The older type 90 wt was causing bearing failures because it made the heat stay with the metal rather than letting the lubricant work like a coolant.



So, the old viscosity means of testing oil - is evidently out the window. Its based on lubricity. According to the Caterpillar engineers the new 80-90 is better and keeps your gearbox cooler.



We'll see, but I'm going to try it.



Mark

[Deleted User]

You should be able to find Lucas oil for the rear axle at any parts store.

[Deleted User]

So, 80-90 is ok to use and Lucas oil is straight 90?



I could not find straight 90 at any parts store.

Geoff

80W-90 EP oil is far superior to straight 90 oil any day.

Geoff.

super651

I gave Mark the wrong oil that i was using. The Caterpillar gear oil that i have been using for the past 9 years in the STD trans with OD and in the Diff. is Viscosity -60-Cat-API--FDAO. Comes in 5 Gal only Part #184-6022. our testing showed a 10 degree lower temp on the diff.and 8 on the Trans. ( we used Heat-Test-Strips on the housings to get the reading) This was compared to the normal 80-90 Wt.oil + easy shifting in the winter.

The 80-90 Wt oil from any supplier runs much cooler than the old 90 Wt and is the one to use if you dont want to buy 5-Gal of Cat Oil

Hope this helps Rudy.

[Deleted User]

This is great and timely information as a diff flush and fill are coming up on the list.