Front TJ Rubicon Dana 44 axle won't unlock


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Dec 13, 2017
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Missouri, United States
My front Dana 44 axle seems to be in locked-in mode (2003 TJ Rubicon). Jeep is on the rack, no compressor attached to diff hose, and both wheels spin forward together. Hooked up my Mighty-Vac & can actuate rear locker but no unlocking (deactivating) in front (still locked in). I know they lock in with about 4psi. Jeep was in an accident & struck in left front corner. Upper & lower control arm replaced. Getting ready to pull the diff cover & unsure what to look for when I get in there. So I'm reaching out to the group again for some insight.
 

Alex M.

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Try pulling the fill plug. If the plug is installed too tight it can bind the locker actuator ring.

There are actually torque specs on the fill plug. The Rubicon has a magnetic plug and the placement is directly over the locked rear locker. If it's in too far the actuator ring will gouge the magnet and get wedged in place.

EDIT: oops, I thought you were talking about the rear locker.
 

Chris

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Did the lockers work before the accident, or have they never worked since you bought the vehicle?
 

Jerry Bransford

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Try pulling the fill plug. If the plug is installed too tight it can bind the locker actuator ring.

There are actually torque specs on the fill plug. The Rubicon has a magnetic plug and the placement is directly over the locked rear locker. If it's in too far the actuator ring will gouge the magnet and get wedged in place.
X2, try completely removing the fill plug and see if the locker unlocks while performing a couple S-turns which will help it to unlock more easily.
 
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John Middleton
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Did the lockers work before the accident, or have they never worked since you bought the vehicle?
No, fully functional prior. Got in three days wheeling in Moab. I previously had problems with rear locker but a new air pump fixed that. Did weld new lower control arm brackets onto axle after one was bent from the accident. No visible damage to axle itself.
I did pull front fill plug—no joy!
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I noticed Jerry, you regeared your diffs in the past. Saw the ring air bladder in a pic from one of your posts. I’m perplexed because default is unlocked?? Back at work till Friday but trying to formulate an attack plan for next weekend!
 
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John Middleton
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Got back on my Jeep yesterday & pulled the front diff cover. Nothing looks amiss except this small pin partway out of the spider gears. Tried to advance it back in gently with no movement. Locker air mechanism moves appropriately (using mightyvac to pressurize). Might be time to seek professional help.
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New Transfer case installed, both driveshafts rebuilt, and finishing up transmission drain & fill today with trans temp port added to pan.
 
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Anrew

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Please let me know an update for this. this has happened to me over the weekend. Same situation with the front being locked, same pin in question (not sure if thats normal). Thanks!.
 
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John Middleton
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I think the spider gear pin keeper is ok. My Rubi was tboned in an accident in Moab in March. Working thru issues (new control arms, tcase & driveshafts rebuilt $, I then found the front diff was locked in.
Long story short, front diff was bent which was causing diff locker gears not to release. Once I pulled axles, carrier freed up. I am in process of trying to straighten differential housing with some success. Biggest problem is getting a point to accurately measure where my alignment is. Once I have it trued, I plan to truss it for future strength.
See next post for followup.
 
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John Middleton
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Takes a LOT of heat to bend back axle. Rosebud didn't do it. Preheat with propane weed burner & use rosebud for spot heating moved it back into place. I'm using 1" (1 3/8" od) water pipe to gauge alignment with rest of axle. Any better suggestions appreciated! Need one more session to bring it into final place. Jeep in background is the '03 Rubicon I bought because I am missing Whitey sooo much.....but that's another story! I'll post more as project evolves.
 
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Jerry Bransford

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Nice job. I would just suggest supporting the jack stand with a large enough piece of plate steel on the I-beam to support it at its strongest points, its legs, not by its leg braces straddling the I-beam.
 

Jerry Bransford

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Good thought! I have better stands but couldn’t track em down for this project.
The jack stand itself is fine, it's just not being properly supported via its leg braces for the load that bottle jack will be exerting to straighten the axle. Those skinny braces welded between the legs aren't strong enough to support the load they're being subjected to. Just the legs are. :)
 
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John Middleton
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Roger that! More interested in a better way to accurately measure alignment. 1” water pipe down the center thru the seals is close but I’m wanting more than eyeball precision before I weld the trusses on.
 

Ted

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Please let me know an update for this. this has happened to me over the weekend. Same situation with the front being locked, same pin in question (not sure if thats normal). Thanks!.


Mine is at 4 wheel parts after an accident. I was told that isn't normal for the pin. They said it held the larger pin in place that holds the spider gears.
After the accident, the differential started grinding. Engage the locker and it went batshit crazy. I ordered a new set of Revolution axles from Allen thinking that I would fix it myself. Insurance is replacing it all with a fully built G2 Core 44 axle with ARB. To replace it with a stock setup from the stealership is about $1000 more
 
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