Solid Differential cover fluid fill
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JK Super Freak
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From: Middle of no where
Solid Differential cover fluid fill
I hate asking this question, but I have yet to find the correct answer, I know there has to be one. I used the search function, there are thousands of posts with different answers on how much to fill the diff (44 front and rear) with the solid covers. Solid states 1.5-2.3(whatever that means), some say 1.5, some say 1.3, some say "little less that two". What is the correct answer? Also, is it ok to use 75w90 in the front and rear, manual states to use 75W140 in the rear?
JK Jedi Master
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From: O HI 4 Lo
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JK Junkie
Joined: Sep 2007
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From: Long Island, NY
I use 75-140 all around because of the 35's...
And as far as filling it goes... I make a dip stick out of a zip tie, and fill it just above the top of the bolts at the bottom of the axle tubes.. dont know if it is correct, but its the same location as the OEM diff cover..
If I were to do it again, I would go with a Teraflex cover because it has 2 fill holes, one at the OEM location, and one higher for lifted Jeeps.. Best design IMO
And as far as filling it goes... I make a dip stick out of a zip tie, and fill it just above the top of the bolts at the bottom of the axle tubes.. dont know if it is correct, but its the same location as the OEM diff cover..
If I were to do it again, I would go with a Teraflex cover because it has 2 fill holes, one at the OEM location, and one higher for lifted Jeeps.. Best design IMO
JK Jedi Master
Joined: Mar 2007
Posts: 14,800
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From: Midwest City, OK
First off, I'm not a mechanic. So don't attribute authority to this answer because you think I am. However, having seen this question asked a bazillion times, this is what I've learned:
There's only one correct answer, and it's the easy, most obvious one: Fill it to just the same height as you would if it had the stock covers on it (which was to the fill port). Since after-market covers have the fill port higher up, that means you probably won't fill it to the fill port; you fill it to below the fill port. The reason the fill port is higher up on after-market covers is because they're designed to be used with a lift, which means that the axle may have rotated (shifting the location of the fill port). So they are higher up to allow for that. The reason for not filling to the port is because too much oil can get churned up and start foaming. That is bad, and will result in foamy oil blowing out your breather tube, and foamy oil is not as good a lubricant.
BTW: Because after-market covers typically have a slightly larger volume, the right answer is not "the same amount as the stock covers." It's not the amount that's at issue--it's the LEVEL of the oil. The Zip-tie dipstick method previously mentioned works nicely.
Finally, there's a nice picture of where, exactly, the oil level should be. If you want that, I'll let you use search some more. As you said, this question has been asked a bazillion times and there are plenty of answers--unfortunately mostly incorrect.
Regarding viscosity: The manual specifies the lubricant, and, at least for '07, has an exception for those who tow trailers. I'd suggest following the manual, but admit to putting the same viscosity in both axles.
There's only one correct answer, and it's the easy, most obvious one: Fill it to just the same height as you would if it had the stock covers on it (which was to the fill port). Since after-market covers have the fill port higher up, that means you probably won't fill it to the fill port; you fill it to below the fill port. The reason the fill port is higher up on after-market covers is because they're designed to be used with a lift, which means that the axle may have rotated (shifting the location of the fill port). So they are higher up to allow for that. The reason for not filling to the port is because too much oil can get churned up and start foaming. That is bad, and will result in foamy oil blowing out your breather tube, and foamy oil is not as good a lubricant.
BTW: Because after-market covers typically have a slightly larger volume, the right answer is not "the same amount as the stock covers." It's not the amount that's at issue--it's the LEVEL of the oil. The Zip-tie dipstick method previously mentioned works nicely.
Finally, there's a nice picture of where, exactly, the oil level should be. If you want that, I'll let you use search some more. As you said, this question has been asked a bazillion times and there are plenty of answers--unfortunately mostly incorrect.
Regarding viscosity: The manual specifies the lubricant, and, at least for '07, has an exception for those who tow trailers. I'd suggest following the manual, but admit to putting the same viscosity in both axles.
Last edited by Mark Doiron; Nov 3, 2009 at 07:53 AM.
JK Jedi Master
Joined: Oct 2006
Posts: 15,133
Likes: 0
From: O HI 4 Lo
First off, I'm not a mechanic. So don't attribute authority to this answer because you think I am. However, having seen this question asked a bazillion times, this is what I've learned:
There's only one correct answer, and it's the easy, most obvious one: Fill it to just the same height as you would if it had the stock covers on it (which was to the fill port). Since after-market covers have the fill port higher up, that means you probably won't fill it to the fill port; you fill it to below the fill port. The reason the fill port is higher up on after-market covers is because they're designed to be used with a lift, which means that the axle may have rotated (shifting the location of the fill port). So they are higher up to allow for that. The reason for not filling to the port is because too much oil can get churned up and start foaming. That is bad, and will result in foamy oil blowing out your breather tube, and foamy oil is not as good a lubricant.
BTW: Because after-market covers typically have a slightly larger volume, the right answer is not "the same amount as the stock covers." It's not the amount that's at issue--it's the LEVEL of the oil. The Zip-tie dipstick method previously mentioned works nicely.
Finally, there's a nice picture of where, exactly, the oil level should be. If you want that, I'll let you use search some more. As you said, this question has been asked a bazillion times and there are plenty of answers--unfortunately mostly incorrect.
Regarding viscosity: The manual specifies the lubricant, and, at least for '07, has an exception for those who tow trailers. I'd suggest following the manual, but admit to putting the same viscosity in both axles.
There's only one correct answer, and it's the easy, most obvious one: Fill it to just the same height as you would if it had the stock covers on it (which was to the fill port). Since after-market covers have the fill port higher up, that means you probably won't fill it to the fill port; you fill it to below the fill port. The reason the fill port is higher up on after-market covers is because they're designed to be used with a lift, which means that the axle may have rotated (shifting the location of the fill port). So they are higher up to allow for that. The reason for not filling to the port is because too much oil can get churned up and start foaming. That is bad, and will result in foamy oil blowing out your breather tube, and foamy oil is not as good a lubricant.
BTW: Because after-market covers typically have a slightly larger volume, the right answer is not "the same amount as the stock covers." It's not the amount that's at issue--it's the LEVEL of the oil. The Zip-tie dipstick method previously mentioned works nicely.
Finally, there's a nice picture of where, exactly, the oil level should be. If you want that, I'll let you use search some more. As you said, this question has been asked a bazillion times and there are plenty of answers--unfortunately mostly incorrect.
Regarding viscosity: The manual specifies the lubricant, and, at least for '07, has an exception for those who tow trailers. I'd suggest following the manual, but admit to putting the same viscosity in both axles.
