06 Rubicon front axles won't engage

Long Rider

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Okay, time for my first post, and it's going to be about what an idiot I am. I just bought a really nice 06 Rubi. I ran her through the gears including 4 lo and everything seemed to be working fine. Well, it turns out it doesn't engage the front drive shaft. How screwed am I? What can I do to trouble shoot it? What can I do to fix it? It grunted like it was supposed to in 4 low so I know it went to the lower ratio for the rear wheels, but the front wheels don't seem to be engaging in 4 low or high.

Any help would be appreciated. Yes, I used the search function first before posting.
 
Does the 4wd light engage on the dash? Can you engage the front locker?

Take it to some dirt and see if only the rear wheels are spinning when you love on the skinny pedal a little.
 
It has a front drive shaft.
I can drive the front tire up to a corner of a concrete ramp and it will not crawl over it.
I give it gas enough to make the rear tire spin, and still nothing. Also, I thought Rubi rear ends had limited slip as well as a locker, so shouldn't the limited slip turn both the tires?
The 4X4 and the locker lights do not come on.
 
. . . It grunted like it was supposed to in 4 low so I know it went to the lower ratio for the rear wheels, but the front wheels don't seem to be engaging in 4 low or high. . . .

What is "it" and what do you mean by "grunt?" From your description it cannot be determined whether or not you were actually in low range.

Compare the rpms at particular low speeds (5, 10, 15) in 2WD and in 4WD low range. Please report whether a difference in rpms at a given speed confirms that you have successfully shifted into low range, not just the position of the transfer case shift lever. Also, please note for us when the 4WD dash light turns on and off, blinks or stays solid, etc. as you shift to the various positions for the transfer case.
 
What I mean when I say "grunt" is first gear is obviously in a lower gear when I shift it to four low. The frame tries to twist, as if it is trying to lift up a front tire. I can run through all six gears in about 100 ft. It's like I'm in a TJ, then I pull the lever to 4 low and Boom!, I'm back in the old Willys I had in high school with 5;38 gears.

The 4WD light does not come on at all, nor does the locker ligtht when I toggle the switch.
 
What I mean when I say "grunt" is first gear is obviously in a lower gear when I shift it to four low. The frame tries to twist, as if it is trying to lift up a front tire. I can run through all six gears in about 100 ft. It's like I'm in a TJ, then I pull the lever to 4 low and Boom!, I'm back in the old Willys I had in high school with 5;38 gears.

The 4WD light does not come on at all, nor does the locker ligtht when I toggle the switch.

Jack up a front tire, shift to 4L or 4H, and try to spin the tire by hand. If you can't spin the tire by hand, your front axle is engaged. If the front axle is in fact engaged, seems like the most likely culprit is the t-case position sensor. This would cause the dash light to not light up and would prevent locker activation. If you can spin the front tire by hand, your front axle is not engaged. Given the fact that you say your front driveshaft is present, and you can select low range, that sounds like some unusual problem inside the t-case
 
My suspicion is that the transfer case shifter has slipped and that you haven't actually shifted into what you think you have. 4low on a Rubicon is dramatically different than 2h/4h and will have no trouble climbing a curb.

Also, it is best to not spin the tires too much with the rear LSD. It has its limits and it doesn't die with any grace.
 
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I had same issue with lights and lockers on my 06 Rubi. Found out the plug for the selector switch on the transfer case was broken and unplugged. Go under from the driver side at the rear of the skid plate. Look and/or reach past the air setup and see if the pigtail is plugged in first. I rebuilt mine with new wire and reused the same connectors from inside the pigtail. Hopefully yours is just unplugged. If not, I would start by seeing if you get power to the pigtail and if you can’t, replace the switch.
 
My suspicion is that the transfer case shifter has slipped and that you haven't actually shifted into what you think you have. 4low on a Rubicon is dramatically different than 2h/4h and will have no trouble climbing a curb.

Also, it is best to not spin the tires too much with the rear LSD. It has its limits and it doesn't die with any grace.

I understand what you are saying, but if you read what I wrote, you will see that it IS dramatically different in 4 LOW. That's what I was calling "grunt". The curb in question was a concrete ramp. I placed the Jeep so that the drivers side front tire was on flat ground and the passenger side was up against the side of the ramp, where it was about 15 inches high.

I figured since it had 33 inch tires, trying to climb a 90* embankment at about axle level would be a simple way to tell if the front axle was engaging without calling attention to myself or thrashing the Jeep in the city. While, I could have given it more throttle and bounced over the obstacle, getting over it was not my goal. seeing if the front end engaged was.

Also, I got the right rear tire to spin only. The drivers side just sat there. Granted, I was trying not to call attention to myself, so i didn't "light 'em up", but I am concerned that the LSD might not be functioning either. I crawled underneath, and the rear IS a 44 with disk brakes, so chances are it's a Rubi rear. Meh, II'll worry about that later. Sorting out used cars always generates more than a few fish to fry.

Thanks for your time in writing a response.
 
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Jack up a front tire, shift to 4L or 4H, and try to spin the tire by hand. If you can't spin the tire by hand, your front axle is engaged. If the front axle is in fact engaged, seems like the most likely culprit is the t-case position sensor. This would cause the dash light to not light up and would prevent locker activation. If you can spin the front tire by hand, your front axle is not engaged. Given the fact that you say your front driveshaft is present, and you can select low range, that sounds like some unusual problem inside the t-case

Great idea, I'll do that today when I get off work. I'm thinking there's something going on with the T-case as well. I'm familiar with guts of the old T18 and T30s, but not these chain driven jobs. I'm not sure when, where and how power is transfered through the gear box in 2 wheel drive, 4 HI and 4 LOW. Thank you for your time!
 
I am not convinced that you actually shifted the transfer case into low range. Actual rpm's at given speeds in the same transmission gear in what you believe to be high range and again in the same transmission gear in what you believe to be low range would tell us a lot more than words like "grunt" and phrases like "dramatically different."

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BTW, you can also check to see if 4WD is working or not and whether or not the transfer case is shifting into the desired position by putting your jeep on jack stands or a lift and observing various gear and transfer case combinations with all four wheels off the ground.
 
I had same issue, but neither axle would lock. There was a relay not re-laying. The mess of crap on the drivers side rear of the skid plate is for the locker activation switches. Check the easy stuff before ripping into the transfer case. Could be an air hose, some rusty connection. If it is going into low range when you pull the lever then the transfer case is probably not the problem.
 
Is it possible that the previous owner installed a 2 low/ 2 WD kit on the Jeep? It might be worth trying to bump the range selector forward a bit and see if it engages 4 low. The 2 low shift pattern would be 2 hi > 4 hi > N < 4 low < 2 low.
 
[QUOTE
2Low usually comes before 4low:
[/QUOTE]
You are correct. I had it backwards in my mind.