Jeep jk locks up in 4x4

Dstrick88

New member
I have a 2008 Jeep Wrangler unlimited Sarah 4x4 automatic. 3” lift 35” tires.

Current issue I’m having: the Jeep drives fine in 2 high with no issues. When I shift it into 4x4 high or low, the car rolls about a foot then the locks up. Locking up meaning the front tires drag and will not drive, put it in reverse and it rolls about a foot back and locks up again. I’ve check and changed the oil in the front and rear diffs, no signs of damage. Hasn’t been re-geared. I replaced the lower transfer case cable bushing and the one on the gear selector is fine. I’m at a loss as to what’s causing this issue, I’m going to change the fluid in the transfer case to see if this helps. Any ideas?

Does the transfer case cable need adjusted when the vehicle is lifted?
 

QuicksilverJK

Caught the Bug
You are definitely on the right track. Front and rear diffs spin regardless of if it's in 4wd. It sounds to me like either something came apart in your transfer case, or you aren't getting full engagement. Have you tried shifting the transfer case in a slow roll? Obviously try this very slow the first time so that if it does lock up you don't grenade anything.


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As mentioned above, definitely a T-case issue. I'd suspect worn shift linkage first as that's a cheap fix.

Be careful and don't force it at all or you'll end up with a blown case.
 

Dstrick88

New member
Yes tried to slow roll, and tried bumping it into drive and back to neutral several times with no luck.

You are definitely on the right track. Front and rear diffs spin regardless of if it's in 4wd. It sounds to me like either something came apart in your transfer case, or you aren't getting full engagement. Have you tried shifting the transfer case in a slow roll? Obviously try this very slow the first time so that if it does lock up you don't grenade anything.


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Time to take apart the t case. There’s nothing in it that should be able to stop rotation, something must’ve broke inside. It’s just weird that it goes back to normal once shifted back to 2hi. No noises in 2? Will it let you physically shift to high neutral and low?


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Dstrick88

New member
Time to take apart the t case. There’s nothing in it that should be able to stop rotation, something must’ve broke inside. It’s just weird that it goes back to normal once shifted back to 2hi. No noises in 2? Will it let you physically shift to high neutral and low?


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No noise in 2 high, I can shift it into all gears including neutral. I get some resistance but it goes back to 2 high and drives fine. My thinking is it’s not fully engaging.


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No noise in 2 high, I can shift it into all gears including neutral. I get some resistance but it goes back to 2 high and drives fine. My thinking is it’s not fully engaging.


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I agree, sounds like it's not shifting fully in to 4.
Have someone shift it in the cab, while you watch the linkage move underneath. Then see if you can move it manually from underneath and have it complete the shift.

Obviously, make sure parking brake is set and the vehicle is not in drive or reverse. Safety first.
 
No noise in 2 high, I can shift it into all gears including neutral. I get some resistance but it goes back to 2 high and drives fine. My thinking is it’s not fully engaging.


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I hope that’s all it is for ya but that doesn’t make sense to me. When it doesn’t fully engage at the linkage you get grinding and popping out of gear or popping into neutral. You described it still sending normal power to the rear but completely stopped front axle from turning which makes me think it’s something internal like the fork or sliding clutch jammed on something broken not allowing the chain to turn. But I haven’t been inside a jk’s t case personally, disclaimer.


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jdofmemi

Active Member
It sounds to me like it is not disengaging the high range gear, and then when low engages it binds up. Shifting back to high, low disengages like it should and everything works.

What I don't know is what could be causing it, as I haven't been inside of one of these so I'm not sure how the shift mechanism is set up.
 

Dstrick88

New member
It sounds to me like it is not disengaging the high range gear, and then when low engages it binds up. Shifting back to high, low disengages like it should and everything works.

What I don't know is what could be causing it, as I haven't been inside of one of these so I'm not sure how the shift mechanism is set up.

From the research I’ve done Jeep t case issues are a dark hole, everyone knows how to replace a bushing but not much besides that.


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fiend

Caught the Bug
Disconnect your drive shafts from the TC and disconnect the TC shift cable at the TC. Then try to shift the TC at the TC between 2H, 4H, N, and 4L while someone else is in the cab working the transmission. If everything works fine then you’ve eliminated the TC as your problem. If you still have the problem, then you’ve probably ruled out the linkage and anything at the axles.


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Dstrick88

New member
Changes the transfer case fluid and didn’t see any metal flakes. Drove it after and still having the same issue. More than likely will take it to my 4x4 shop at the end of the month


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