Transfer Case won't shift right

I have a `95 XJ with the NP242 case and recently I have been having trouble shifting it. The 4WD lights on the dash stopped coming on too. I can shift into 4WD High Part-Time and 4WD Low, but not 4WD High Full-Time. Could the linkage be messed up? What is the right way to adjust the linkage? Thanks

anybody?

My NP242 is doing same thing ... it started this behavior after a shop split the case and installed a SYE. Maybe a coincidence ... maybe not ... no way tell without having someone that really knows this t-case diagnosing the problem.

My light finally went out also ... at first, when I picked it up, the Part-Time 4wd light was dimly lit, ... coming on and off intermittently when in 2wd---after a week the light went out. I just thought the switch in the case was failing or connectivity was disturbed due the shop dunking the case in a solvent tank.

But recently I found when trying slip it into Part-Time and Full-Time 4wd ... the light doesn't come on at all ... and it seems like it's not engaging in 4wd like it did before the case was split---like it's only partially engaged. I can't feel when the t-case engages ... like it did before all this work was performed.

So ... has the switch gone bad ? ... or maybe linkage is out of adjustment ? ... or something more serious ?

A dealer won't touch it now that a SYE is installed.

It would be nice to know how the vacuum switch works ... the FSM says nothing about this problem ... or how the switch is activated.

Maybe someone here can elaborate.

I have absolutely no first hand experience with the 242, but.....

on my 231, the light on the dash can only come on if the (piece I don't know the name of) is in the correct position. It depresses a spring loaded button a certain amount which signals which range you are in. Purely mechanical.

The light will not come on, assuming electrical is fine, unless the t-case is fully in gear. So, unless your wiring is bad, or the bulb is burnt out, the t-case isn't fully in gear.

Again, I have no experience how the 242 works, but that is how my 231 works; maybe they are the same.

bchulett, mine did EXACTLY the same thing. The Part-Time light kinda came on and off randomly while in 2WD. Now it never feels like the t-case is engaged when i try to put it into 4WD. I want to try to adjust the linkage, does anybody know the right way to do it?

baseballneal86 said:

bchulett, mine did EXACTLY the same thing. The Part-Time light kinda came on and off randomly while in 2WD. Now it never feels like the t-case is engaged when i try to put it into 4WD. I want to try to adjust the linkage, does anybody know the right way to do it?

Click to expand...

Neal,

I'm not one that enjoys misery .... but at this point, I'm glad I've got a friend out there with the same problem. The FSM diagram indicates a wire going to a "vacuum switch" located on the tailcone section of the case ... the NP231 has the same "vacuum switch" but it's located on the front section of the case ... this is the ONLY switch on the case ... including the linkage.

BTW: I don't see this "vacuum switch" as a "mechanical" device .... ?? I could be wrong due to the diagram ... but it doesn't appear to come into contact with anything ... hence being vacuum activated.

I've been thinking about changing that switch before tearing anything apart ... here's the procedure to adjust the linkage:

(1) Remove the shift lever bezel.

(2) Move the shift lever into 4L position.

(3) Insert a 3 mm (1/8") spacer between the shift lever and forward edge of the shift lever gate (fig. 4). Secure the lever and spacer in place with tape or wire.

(4) Raise the vehicle. <--- it doesn't say how high

(5) Loosen the trunnion lock bolt (fig. 5). Linkage rod should now slide freely in the trunnion.

(6) Verify that transfer case range lever is in 4L position.

(7) Position the linkage rod so it is a free fit in the range lever (fig. 5). Then tighten the trunnion lock-nut.

(8) Lower the vehicle.

(9) Remove the shift lever spacer and install the bezel.

If you try this let me know how it goes .... if you want me to fax you those pages next week .... leave me a PM.

Bob

PS: Mine did this subsequent to the SYE and RE 4.5" lift installaion ... using 1" transfer case drop spacers too boot. The combination of the three may have tweeked the linkage out of adjustment ... I hope this hasen't damaged my t-case.

Hopefully it won't rain tomorrow and I can get out to adjust my linkage. If you could send the pages from the FSM to me that would be great. You can email them to [email protected]. I will let you know how it goes.

Well I went out today and adjusted the linkage on my t-case. It helped a lot with being able to shift, but the light only comes on in Full Time 4WD. I know my electrical is fine because the light does come on, just not in Part Time.

Also, I get a scraping/grinding noise whenever I accelerate from a stop. Could my rear main bearing be shot? I have just replaced my tranny mount and both engine mounts? What are some other possible solutions? Thanks

baseballneal86 said:

Well I went out today and adjusted the linkage on my t-case. It helped a lot with being able to shift, but the light only comes on in Full Time 4WD. I know my electrical is fine because the light does come on, just not in Part Time.

Also, I get a scraping/grinding noise whenever I accelerate from a stop. Could my rear main bearing be shot? I have just replaced my tranny mount and both engine mounts? What are some other possible solutions? Thanks

Click to expand...

I bet your front drive shaft is rubbing up against the body.

Maybe. I am gonna pull my front shaft in a few days and see if the noise goes away. That will definetly narrow the possibilities

This is an NP 231, couldn't find a diagram for the 242.

Part 19, the shift mode selector, keeps the t-case in gear. It has grooves on it that bump over a spring loaded button. It is the shaft that the 9/16 bolt goes to off of the linkages. When the linkages move, this thing is what rotates.

The button keeps part 19 in place, thus keeping the t-case in gear. It also means the button is depressed a certain amount with part 19 in different positions.

The amount it is depressed corresponds to what mode the t-case is in and translates to what light shows up on your dash.

I have no idea if it is the same on the 242, since I can't seem to find any diagrams of it, but I can only assume they are similar, since the 242 just has an extra differential in it, and slightly different shift mode selector.

If you all are still having problems, I would suggest you crack your t-case and have a look around. If you have never done it before, it really isn't too scary. There are tons of places online that walk you through the whole thing.

If you don't want to do that, jack the jeep up and put it in 4 wheel drive to see if everything is working.

Hope this helps you guys out.

This is a 242. Just found it. Looks might similar to my 231. Although the picture sucks, it looks like the shift mode selector is almost identical.

Greg,

I've got similar diagrams in my FSM ... and I appreciate your help here ... the only thing I can't figure out is where the "switch" or "switches" and electrical connection is located on that "Shift Sector" or any linkage around it.

Is there a switch and wire located somewhere around this part ?

I looked at the FSM wiring diagram ... it only shows an electrical connection leading to the transfer case tailcone section on a 242 (part 16), and to the front of the case on a 231 (part 7).

Quote from the "Electrical, Heating Emissions FSM" section; "Instrument Panel, 4WD Indicator":

"The 4-wheel drive indicator lights when the vehicle is engaged in Full Time 4-wheel drive mode. The Part Time indicator lights when the vehicle is in a part time 4-wheel drive mode. Voltage is provided to one side of the indicators. Switches in the transfer case area are connected to the other side of the indicator. When the switch is closed, a path to ground is provided and the indicator lights".

It bascially says the same thing for a 231 ... except it references "A Switch" ... not "Switches".

What's up with that ??

I'm totally confused by all this ...

I'm a little drunk, so pardon me if I screw up somewhere.

"Is there a switch and wire located somewhere around this part ?"

I could have sworn the button was the switch (#10 diagram 242), but I'm starting to doubt myself. I might check this out tommorrow. Have you crawled underneith and checked stuff out yourself? Have a look see for wires. The one that goes to #11 on diagram 242 is your speedomoter wire.

If we make this go to 2 pages, more people might read it and respond... arty:

I'll get back to you in the morning

I could have sworn the button was the switch (#10 diagram 242), but I'm starting to doubt myself. I might check this out tommorrow. Have you crawled underneith and checked stuff out yourself?

Click to expand...

Yes, I've crawled underneath it .... the #10 part on the 242 is a "Detent Pin, Spring and Plug" ... indicated the same on the 231.

Have a look see for wires. The one that goes to #11 on diagram 242 is your speedomoter wire.

Click to expand...

You're right, my mistake ... but there is also a "Vacuum Switch" (#16 diagram 242) that screws in the back of the case (not shown well) with a wire harness running to it ... it's right below the speedometer cable.

The same "Vacuum Switch" (#7 diagram 231) is located in front of the case on the NP 231.

I wish I knew exactly what function this "Vacuum Switch" serves .. and how it gets activated from within the t-case---one would think this would be a mechanical switch like you mentioned before.

I need a beer.

Yeah, you're right. The switch on mine isn't the button, but part #7 as you said. It is above the shift mode selector on the 231. It appears you then are correct about the position of it on the 242.

Now that we've settled this useless point (which I insisted we pursue) the matter at hand:

Testing this switch it seems, would involve removing it, and stomping on it like a monkey until its problems are revealed. Seriously though, I'm at a loss as to assertain whether it is functioning correctly.

If it were me at this point, I would split the f***er and settle my curiosity once and for all. But thats just me. As of right now, it sounds like maybe this damned switch is bad. Perhaps contact a dealer for a new switch and see if you can coax them into diagnosing the problem at the same time?

I feel your pain. Unfortunately I think I've done all I can. My supply of knowledge has been exhausted. Happy wrenching.