How much and what weight diff fluid for front RUBICON d44 axle?
08-23-2012, 07:44 AM
#21
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I remember when I was a kid, my father had a 67 Impala SS that he bought new. He was working on something in the trunk (I don't remember exactly what) for which he had to remove the spare tire. That's when he discovered a bagged sandwich and glass bottle of Coca-Cola undercoated/sealed to the inside of the trunk way up near the rear seat (the trunks were HUGE on those things). This was in 1970 or so -- fortunately, the undercoating kept the sandwich from smelling ripe until the "seal" was cut. Apparently napping in the trunk on your lunch break was all the rage at the Chevy factory back in 66-67. And it's only been downhill from there, IMO, when it comes to the "give-a-crap" factor of the Big 3.
So I'm not assuming that the factory put the right weight oil into the differentials on my Rubi. Just my
08-23-2012, 11:01 AM
#22
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Well you could try to blame the guys in Toledo but the axle came from a Dana plant. I would guess Jeep specifies 80w90 for CAFE to Dana, but their too cheap to use synthetic which explains why we have such sort maintenance intervals. I'll be switching to some Mobil 1 75w90 that I've got laying around in the front and I'll see what Summit has in stock when I wander over there next week. GM starting using synthetic axle lube 10 years ago, it's a shame if jeep isn't on board by now.
08-23-2012, 11:30 AM
#23
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Well you could try to blame the guys in Toledo but the axle came from a Dana plant. I would guess Jeep specifies 80w90 for CAFE to Dana, but their too cheap to use synthetic which explains why we have such sort maintenance intervals. I'll be switching to some Mobil 1 75w90 that I've got laying around in the front and I'll see what Summit has in stock when I wander over there next week. GM starting using synthetic axle lube 10 years ago, it's a shame if jeep isn't on board by now.
Even the DealerConnect site doesn't agree with the OM, and the dealer that I go to (as well as some others, according to this thread) uses 75W-140 Synthetic front and back regardless of what the OM calls for.
So my point is that maybe the folks at the factory filled it with 80W-90 generic lowest-bidder gear oil because Chrysler's cheap and/or wants to give revenue-generation opportunities to the dealers; or maybe they filled it with 75W-140 Synthetic because someone noticed it had the tow option; or maybe all the axles are filled the same based on policy; or maybe nobody really gives a crap and puts in whatever's handy. So to be sure, I'm going to put in Mobil1 75W-140 to make sure it's got in it what I think it's got in it.
And I also picked up some Royal Purple Synthetic ATF for the transfer case. I'd have used the Mobil1 synthetic instead because I like Mobil1 (and it's a bit cheaper than Royal Purple -- and I always thought that Mobil1's price was steep), but it didn't have ATF+4 listed on the back, and the Royal Purple did.
Last edited by Gort; 08-23-2012 at 11:32 AM.
08-23-2012, 01:00 PM
#24
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Originally Posted by Gort
I talked to the parts manager while I was there today to buy the super-secret-special transfer case oil for the NV247 in my Grand Cherokee. I asked him about the the friction modifier for the Rubicon axles. He spent 10 minutes in front of his computer looking at the DealerConnect site, then ran out to the shop to ask one of the technicians.
His answer was NO, you DO NOT need the friction modifier in the D44 lockers on the Rubicon.
Other interesting items that came up in the conversation were that this dealer, too, runs 75W-140 in both front and back axles, even on the Grand Cherokee, which calls for 80W-90 front and back unless towing, with the same towing recommendation as the Wrangler (75W-140 in the rear).
Interestingly enough, even though the OM on the GC calls for 80W-90 in the front, the DealerConnect page he printed for me called for 75W-140 in the front.
Also, the GC with the QuadraDrive needs the friction modifier in both front and rear axles (apparently has a limited slip axle in the front, too) according to DealerConnect but not according to the manual. One bottle per differential.
Point of all this Grand Cherokee talk is that what the DealerConnect site says and what the OM/Window Sticker says are apparently two different things. He couldn't find anything on the DealerConnect site stating the need/no need for friction modifier in the Rubi lockers, which is why he went out to the shop to talk to a tech.
08-23-2012, 01:25 PM
#25
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Yeah Gort I should have worded that differently. I think they throw the 3.21,3.73 and 4.10's in crates based on gear ratios and call it a day, you would hope they put different weight fluids in them based on tow package or not but who knows. The stock spring thread is an interesting read, it shows no rhyme or reason on some of the combinations that leave the factory and the guys with "heavy duty suspensions" that have gotten oil shocks.
08-23-2012, 03:52 PM
#26
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Rubicon e-lockers do not require any additives regardless of the type of gear oil used. If you use synthetic gear oil, you don't need any LSD additives because they are included in the oil. Don't run synthetic oil with a Detroit Truetrac. If you use conventional oil, you only need an additive if you have a clutch-type limited slip. Conventional gear oil is generally classified as 80W90 or 85W140. Synthetic gear oil is generally classified as 75W90 or 75W140. The heavier weight gear oils are recommended in the rear axle for towing applications. It won't hurt to run the heavier weight gear oils in the front axle except for slightly more fuel consumption. Any quality gear oil will do the job...just don't overfill.
Front JK Dana 30 = 1.05 quarts
Front JK Dana 44 = 1.35 quarts
Rear JK Dana 44 = 2.375 quarts
Front JK Dana 30 = 1.05 quarts
Front JK Dana 44 = 1.35 quarts
Rear JK Dana 44 = 2.375 quarts
08-25-2012, 02:38 PM
#27
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Originally Posted by river2c
Rubicon e-lockers do not require any additives regardless of the type of gear oil used. If you use synthetic gear oil, you don't need any LSD additives because they are included in the oil. Don't run synthetic oil with a Detroit Truetrac. If you use conventional oil, you only need an additive if you have a clutch-type limited slip. Conventional gear oil is generally classified as 80W90 or 85W140. Synthetic gear oil is generally classified as 75W90 or 75W140. The heavier weight gear oils are recommended in the rear axle for towing applications. It won't hurt to run the heavier weight gear oils in the front axle except for slightly more fuel consumption. Any quality gear oil will do the job...just don't overfill.
Front JK Dana 30 = 1.05 quarts
Front JK Dana 44 = 1.35 quarts
Rear JK Dana 44 = 2.375 quarts
Front JK Dana 30 = 1.05 quarts
Front JK Dana 44 = 1.35 quarts
Rear JK Dana 44 = 2.375 quarts
10-22-2015, 06:14 AM
#28
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Its 75w140 front and rear for the rubi as well as the wk(gc unless you have the one that needs additives then the amount differs) i never go by the number of quarts they say. Fill it until you can stick you pinky in and touch it and thats enough or if you want to play it safe, until it comes out of the hole. I do that on my jk and wk and they work just fine.
10-22-2015, 07:00 AM
#29
JK Jedi Master
Some aftermarket covers have the fill hole a lot higher. Even with stock covers, quantity numbers can't be relied upon.
The important thing to know is the oil level needs to be a little higher than the bottom of the inside of the axle tubes so oil can get to the axle shaft bearings.
You can make a little dip stick from a zip tie.
10-23-2015, 04:49 PM
#30
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Do you guys know if anyone has a tech/ spec pdf or theres a site that shows everything? I know the gc's have one called www.wkjeeps.com... it would be nice a benifical if we had one for the jk's as well. Any thoughts?
Last edited by ibeatmyjk; 10-23-2015 at 04:52 PM.