4WD-high does not engage. 4WD-low will.

[Rick Jefferson]

Hi all. Just bought a 2003 Rubicon (manual with lockers). I didnt realize when i purchased it that it does not engage when shifting into 4WD high. There is NO power being transferred to the drive train. It is like being in neutral. When i shift it down to 4WD low, it works and the lockers work.

I drained the transfer case fluid and it was way low! going out tomorrow to get fluid to refill the transfer case and the transmission. I already did both differentials.

Im stumped. Could this be linkage? I would think if it goes into 4WD low then it has to pass through 4WD high to get there.

Back story:
ive got that sinking feeling and buyers remorse. A couple days after i bought it, the check engine light came on. i took care of that with a new crank shaft position sensor and a new gas cap. The rear brakes had to be replaced and when doing that i noticed that i have a bad outter rear axel seal. when i changed the diff fluids, it was like mud. engine oil was like mud. trailer 4 pin light adaptor not working. engine turns over but wont start until the third try. second gear in the transmission is also messed up and it jumps out of 5th wheIn there is no load. The only thing that scares me is the transfercase and tranmission. they are beyond my ability to repair and now im jeep broke. LOL

 

[Bounty__Hunter]

It's possible it could be a linkage adjustment. Look for 4hi on one side or the other from where the shifter stops for 4hi.

 

[JPNinPA]

Does your jeep have a lift or a body lift?

Body lifts, without correction to the linkage or transmission height, stress the linkage and reduces the throw area of the shifter.

Stock transmission fluid gets thick when cold (30 deg)and the transmission kicks out of 2nd a lot.





What was the codes you had for the CEL?

 

[69jeepcj]

I thought I heard some where that the rubicon 4.1 and lockers only work in low. If thats true and you are trying to put it into Hi with the lockers ingaged, that may be why it wont go in. Just seems like I have heard this somewhere, but not sure.

 

[Rick Jefferson]

Good Morning Guys. Thanks for the replys.

Bounty_Hunter - Ill Check that tonight when im back in the garage. Thank You.

JPNinpa - Yes, it has a 6" body lift. I have to check out the linkage tonight. I dont know much about it, was reading my Haynes Manual. I did a lot of research and it seems that most of the problems were not going into 4WD at all or getting from high to low. This puppy drops right into 4WD-H but goes no where. Im changing the transmission fluid and transfer case fluid tonight as well. hopefully this will resolve the issue. The codes were for major emissions and crank shaft postion sensor. they dissapeard as soon as i replaced the gas cap and put on a new sensor. i was hoping that my starting issue was tied to the CPS, but it was not.

69jeepcj - That is correct, the lockers only work in low. I was not trying to engage the lockers. I should have tried them again in 4WD-L but i was out where i didnt want to be stranded when i discovered the problem last night.

Thanks again guys. Ill update tonight after i check things out more closely.

 

[JPNinPA]

JPNinpa - Yes, it has a 6" body lift. I have to check out the linkage tonight. I dont know much about it, was reading my Haynes Manual. I did a lot of research and it seems that most of the problems were not going into 4WD at all or getting from high to low. This puppy drops right into 4WD-H but goes no where. Im changing the transmission fluid and transfer case fluid tonight as well. hopefully this will resolve the issue. ...

Six inch body lift??? Are you sure you don't mean suspension or total lift?
Ditch the Haynes and invest in a Factory Service Manual. There are no mistakes or bad info in them like others.
Use synchromesh for the transmission. ATF I believe for the transfer case.

 

[Rick Jefferson]

Hi All. thanks for the help. Turns out its the linkage. Yeaaaa! It has a lift. Im not that familiar with the different types, the person i purchased it from told me it was not a suspension lift but rather a whole body lift. I dont know the difference.

The 4WD shift is so sensitive, it is just a fraction of an inch between 2wd and 4wd-high. i was jumping right to neutral between 4wdh and 4wdl. also there is no distinct set off between high and low, ie) you dont need to move the shift lever to the side to engage, so ill have to be careful not to jump between them when i shift.

I also put new fluid in the transmission and transfer case last night. I used Penzoil syncromesh in the transmission and autozone ATF+4 in the transfer case. I had replaced the diffs with 80w90 gear oil but after more research, i guess i should secure some 75w-140 since it has autolockers and a tow package.

If attached pics of the shift linkage. if anyone has ideas on how to adjust this so its more like it should be let me know.

Thanks all again for your thoughts.

 

[Bounty__Hunter]

You likely have a small body lift, 1"-2", and the remainder of your lift is suspension lift. The good news is they put a drop bracket on the tub side of the transfer case linkage, so that part is done correctly.

There should be an adjustment nut on the lever side of the transfer case linkage, loosen it to allow the shift rod to slide through the adjustment hole. Once nice and loose, put the transfer case in 4lo by hand. Then move the shifter to 4lo and tighten the adjustment nut.

 

[Sahara707]

My transfer case keep popping out, the fixed it. Teraflex **** linkage bracket. Mounts to the transfer case only. Works great now.

 

[Bounty__Hunter]

Good choice, I've installed a few of those.

 

[Rick Jefferson]

Thanks Bounty_hunter. Ill Check that out.

 

[Sahara707]

Thanks Bounty_hunter. Ill Check that out.

Yeah. Thanks Bounty_hunter.

 

[mcgyver1467]

Had a friend with a Rubicon that did the same thing, he was shifting right over 4Hi. Sorry I'm a little late with the post.