I've gained so much information concerning my Jeep Liberty tolling this, and one other forum, it's amazing how much I did not know about this vehicle until recently.
Just the other day I happened on a thread that discussed changing the differential oil in the axles, and it indicated it should be done about every 15,000 miles...... ......I'm approaching 30,000 miles and never gave it a thought, so this afternoon I pulled my home made skid plate off the front, and dumped the old oil out, and man did it look like it needed changing too.....


The front was easy, drain plug on the bottom, fill plug approx half way up the housing, drained the old, pumped in the new....then off to the back axle....and this is where things got weird.....

The manual says that both front and rear axles have the two plug arrangement, the front has it, the rear does not...no drain plug....????

and the filler plug is a rubber bung, not even a threaded plug.....WTF.....????

I had to unbolt the cover to drain the oil, I've done this on vehicles ranging from Toyota pickups to military surplus M-35's, and I've never seen an axle that didn't have a drain plug / filler plug combination.....
If that isn't weird enough, no gasket......WTF...again.....???
This cover was sealed on with RTV sealant, and thank God I had some in my shop or I would of been screwed until tomorrow morning when the hardware store opens....(actually I always try to keep a tube of it around for such emergencies).....



The silver lining around this cloud was, it gave me the chance to check for metal shavings on the magnet, found some minor...(to be expected)...crumbs stuck to it, wiped it out as clean as I could, resealed the cover with fresh RTV sealant, bolted it back together, and pumped in fresh gear oil.....

Another maintenance task out of the way.......

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2005 KJ Renegade
3.7 Lt. V-6
2.5" Daystar Lift
Thrush Welded Muffler
K&N (Poor Man's) cold air intake
Goodyear Duratrac 245/75-16

90% of all solid axled vehicles do not have a drain plug in them.

The are some,most notable is military vehicles,and most(not all) vehicles with a 3rd member style axle.Look under any Dodge,Ford,and Chevy pickup(solid axle only) or any of there RWD solid axle cars for the last 75+ years and you will not see a drain plug.There is 2 main reasons for that also.

Well I didn't own either my Ford or Dodge pickups long enough to bother with changing the diff oils, had my Toyota for 12.5 years and did that one 3 times. The SFA Toyota had plugs front and rear, the only other vehicles I've done is various surplus military trucks our Fire dept has used over the years for severe storm operations, and we'd change the diff oil after every trip through the salt water.....

So what are the two main reasons Troy, or are you going to leave me hanging on that one.....????

Also...why would the owner's manual say that both have them when they don't.....???

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2005 KJ Renegade
3.7 Lt. V-6
2.5" Daystar Lift
Thrush Welded Muffler
K&N (Poor Man's) cold air intake
Goodyear Duratrac 245/75-16

1--back in the day vehicles were never meant to last over 100k so no need to service the diffs,dino gear oil will last 100k unlike synthetic gear oil.

2--makes you look inside the diff for anything unusual that a drain plug will not reveal.


IFS and lazy people stemmed the drain plugs in today's diffs.Plus I would rather not have a drain plug,just 1 more thing to worry about offroad.

Well I'm glad the military decided to use them, I'm responsible for (3) M-35's with 3 axles each, that's 9 axles that I changed the oil in 4 times this past winter. Of course they also do not have removable diff covers, they're welded on.....

BTW....don't know what Jeep puts in them...dino or synth, but I used the same Mobile dino oil I put in the M-35's.....

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2005 KJ Renegade
3.7 Lt. V-6
2.5" Daystar Lift
Thrush Welded Muffler
K&N (Poor Man's) cold air intake
Goodyear Duratrac 245/75-16

What weight oil is that?

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

75W-90

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2005 KJ Renegade
3.7 Lt. V-6
2.5" Daystar Lift
Thrush Welded Muffler
K&N (Poor Man's) cold air intake
Goodyear Duratrac 245/75-16

Front should be 75-140W Full Syn. Arguably the rear should be too. As far as I know the owners manual in the dash says 75-140 for the front for all kj's 03 and newer, and also states if towing with the vehicle use the 75-140 out back as well.

Agree with above, have never ran anything except for 75/140 front and rear
Full syn all the way
Better than nothing with the dino,
also if you have the Trac-Lok you need the friction modifier additive

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

Straight out of "my" owner's manual....
Front axle - SAE 80W-90 or equivalent
Rear axle - SAE 75W-90 or equivalent...unless I'm towing (which I'm not) then SAE 75W-140

Don't believe me, read it for yourself.....


as for Trac-Lok, here's a cut & paste from my build sheet from Chrysler....


No mention of Trac-Lok or any other type limited slip, so I should be safe without that additive......

You are correct in that the manual does recommend full synthetic, so I may change it again to that, I had the Mobile Dino oil on hand, so that's what I used. Sorry guys but I can't imagine I'm doing any damage by using the Dino oil, and according to my manual the viscosity is right on for the rear, and close enough for the front with 75W-90.......

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2005 KJ Renegade
3.7 Lt. V-6
2.5" Daystar Lift
Thrush Welded Muffler
K&N (Poor Man's) cold air intake
Goodyear Duratrac 245/75-16

Like other things they must of changed along the way.
Funny they recommend one type one year and the next something different.
Nothing changed in the drive line only what they had in the drums to pump in I guess here in Toledo

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

My 2005 specifies the same viscosities as yours.

75W-90 is a fine substitute for 80W-90, it just means the 75 stuff flows a little better at cold temps. Less like honey. At operating temp they are both a 90 wt gear oil.

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05CRD: GDE Hot ECU & TCM tunes, Provent, Cat filter, Facet lift pump, TransGo kit, Florida TC, Samcos, stainless brake lines, HDS thermostat, Renegade light bar,
RL super sliders, Bilstein adjustables, Al's Gen 4.5 Arms, 235/85-16 Duratracs, DTT rear, Elocker front, EVIC+TPMS, Turbo timer, McNally pillar gauges, Weeks Stage II kit.