Does an aftermarket diff cover require more fluid?

[nk24]

I have a Ruff Stuff diff cover on my front Dana 44. When I drained the fluid I got almost 2 full quarts, which didn’t include the fluid that spilled when I pulled the axle shafts. I know the stock capacity is 1.375 quarts. How much should I put back in?

This is the cover I have: https://www.ruffstuffspecialties.com/D44COV.html

 

[CodaMan]

Does it have a fill plug?

 

[hosejockey61]

Stock capacity is 1.89L which is 2 quarts.

 

[nk24]

Does it have a fill plug?

It does, but it seems high.

 

[nk24]

Stock capacity is 1.89L which is 2 quarts.

That’s for the rear though, right? Everything I’ve read is the front takes 1.375 qt.

(P.S. your ball joint video was extremely helpful and gave me the confidence that I could do it myself, thanks!)

 

[hosejockey61]

That’s for the rear though, right? Everything I’ve read is the front takes 1.375 qt.

(P.S. your ball joint video was extremely helpful and gave me the confidence that I could do it myself, thanks!)

Front and rear are the same. The Dana 30 takes 1.2L. Thanks!

 

[nk24]

Front and rear are the same. The Dana 30 takes 1.2L. Thanks!

You’re right. I found it in the FSM (should have looked there first).


From the 2005 FSM:

 

[MaximusLJR06]

You’re right. I found it in the FSM (should have looked there first).


From the 2005 FSM:
View attachment 241335

I'm 99% sure the front 44 does not take 1.89 L and is actually closer to 1.3 L. I just changed mine last week and struggled to get 1.3 L in it and that's about all that came out of it as well. The rear 44's are 1.9 L though.

 

[jjvw]

It does, but it seems high.

If it is high, the oil level will self correct by spitting out of the breather over time while driving. Beyond the mess, this isn't a problem.

 

[TheBoogieman]

Is the "GOOGLE" site "cancelled" again because they offended someone?
From a reputable Jeep site. This hasn't changed since 2003 (Rubicon).
Dana 44 - 2 quarts 80W-90 or 75W-140 *
Rubicon Dana 44 (FRONT) - 1.375 quarts 75W-140 synthetic
Rubicon Dana 44 (REAR) - 2 quarts 75W-140 synthetic **

 

[rouxbicon]

I'm 99% sure the front 44 does not take 1.89 L and is actually closer to 1.3 L. I just changed mine last week and struggled to get 1.3 L in it and that's about all that came out of it as well. The rear 44's are 1.9 L though.

I agree, and I believe the FSM info posted is actually in error. The fill hole in the factory front diff cover of a TJ Rubicon is noticeably lower than the fill hole in the factory rear cover. The front diff does not require quite as much gear lube as the rear because it is not necessary for the level to be high enough to lube the axle bearings.

 

[J&M’s ICON]

You have to remember, all differential fluid capacities are based off stock covers. Picture filling a ball, if you changed stock covers, and your new one is possibly larger, the same fluid level would go down as the ball became larger.

The Ring and Pinion actually get an oil bath as they cycle thru it. The Ring picks up oil as it turns to lubricant the other components primarily.

You don’t want to over fill, but if you changed covers, it may require a little more fluid.

 

[TheBoogieman]

Looks like others don't take their OCD meds.
p.s. What do I do if my 4.0L only takes 5.5 or 5.3 quarts of oil when I change it? Should I just add 6 quarts and not care? This Jeep rocket science is so difficult to understand. I'm so glad I'm a part time brain surgeon "Neurosurgical unit" in Mexico.

 

[hosejockey61]

You can get away with less in the front since there isn't oil going out to lube the axle bearings like on the rear axle.

When we raise our pinions up to account for the lift it makes it very difficult to get the "specified" amount in anyway as it will start leaking out before it all goes in. Get as close as you can and call it good.

 

[nk24]

This cover might be a little too beefy. There is a patch on top of the cover where Currie track bar makes contact with it. I can feel a scrape on the back side of the track bar as well.

Might be time to look for some stock covers.

 

[hosejockey61]

This cover might be a little too beefy. There is a patch on top of the cover where Currie track bar makes contact with it. I can feel a scrape on the back side of the track bar as well.

View attachment 241398View attachment 241399

Might be time to look for some stock covers.

You could do a couple of things. First, you might be able to bend your drag link so it sticks out further than it currently does. Our group find several differences in bend angles. We put some pretty big bends to get them to clear things. The other option if those covers just won't work, get the Currie or Barnett style cover. Reinforced on the bottom where it needs it and stock on the top to eliminate interference issues.