242 will only go into full time, some times..?

First of all, my 4wd lights aren't working - I'll fix that later.

On the highway if I shift from 2wd into 4x4 Full Time, it'll sometimes stick in part time and every 10 seconds or so I'll get a "pop" from the t-case and a jostle in the jeep. I think it's because one of my tires is really low on pressure. Anyways, I took it home and found out that when I put it in full time, even though the lever moves nicely and it sticks in it, it still stays in part time. I hooked up the 4x4 light and it confirms that it's still engaged in part time. Yet if I move the linkage to 4-low and back to full time, it now properly engages full time.

So I'm thinking linkage, right? Well it's not that simple. Thing is, if I were to move it back, I wouldn't be able to engage 4-low. 4-low and 2wd are both on the fine line at each ends of the spectrum and it seems that if I adjust the linkage in any way, I either lose 2wd or 4-low.

What to do? Take out the center console and grind out the metal shifter gate to allow some more movement with the shifter? The bushings and linkage look fine and there's no real excess play.

Do you have a good repair manual? All you may need to do is re-adjust the linkage. I think the procedure is the sam for the NP231 as the NP242.

With the console off, place the t-case in 4LO. Using a 1/8th inch spacer, slide the spacer between the shift lever and the shift gate while in 4LO (all the way at the back). No go under and loosen the trunion bolt. Make sure the shift rod rotates freely in the trunnion and tighten the bolt securely. No go back up top and remove the shim and re-install the console....

poorboy_616 said:

Do you have a good repair manual? All you may need to do is re-adjust the linkage. I think the procedure is the sam for the NP231 as the NP242.

With the console off, place the t-case in 4LO. Using a 1/8th inch spacer, slide the spacer between the shift lever and the shift gate while in 4LO (all the way at the back). No go under and loosen the trunion bolt. Make sure the shift rod rotates freely in the trunnion and tighten the bolt securely. No go back up top and remove the shim and re-install the console....

Click to expand...

Which I've done before. Only thing is, if I do that, I can't shift it into 2wd anymore.

Why did Jeep have to make the linkage so short? On my dad's full size chev, the transfercase shifter can go 2x as far and it only has the options that a 231 has. Rargh!

I would do a search for the Novak shifter here in the forum. I think that would eliminate alot of the difficulties your are having....

hmm yeah but that costs a couple hundred buckaroos. hm.. Might just grind out the gate.

When all else fails, break out the grinder.....

Makes me wonder if the someone swapped IN the 242 t-case.....

The shift gate for the 242 had a slightly longer throw (when looking at the gate) then the 231.....

poorboy_616 said:

When all else fails, break out the grinder.....

Makes me wonder if the someone swapped IN the 242 t-case.....

The shift gate for the 242 had a slightly longer throw (when looking at the gate) then the 231.....

Click to expand...

Yes, that person was me

I swapped the gate out of another Np242 jeep.

I never shift on the hwy. I know the manual says you ca do it..
I shift when I barely move, one continuous movement. If it binds in the PT position I reverse and start moving while applying pressure on the handle.
I think shifting on the hwy, has the potential for trouble. I've had 3 XJs and 1 WJ, all with 242s. They are great but I always wished that the FT and PT positions were swapped.

Is there any excessive slop in the shifter links? That would chew up some of the lever throw.

make sur all the tires are the same size and air pressure is critical with that t-case

I've managed to get it into full time, but every 20 seconds or so I get this 'pop' from underneath and a jostle in the driveline.

Could it be the front disconnect popping out? The chain was tight when I pulled the t-case apart..

The tire pressures are pretty similiar too.

What year is yours??

I don't think the NP242 equipped XJ's used the dosco axle, but I could be wrong.....

poorboy_616 said:

What year is yours??

I don't think the NP242 equipped XJ's used the dosco axle, but I could be wrong.....

Click to expand...

Nor were they behind an AX15

I convereted my '89 BA/10 & NP231 with Vac Disco to an AX15 & NP242 with a permenent washer induced non-disco. however I'm wondering if there's enough play in the fork to let the collar disengage enough now and then.

T-case is from a 91.

That or the transfercase is somehow fucked? It looked fine when I tore it apart. Here's some pics:





Key note is that on the second picture, if I were to keep the two shafts seperate (as they were being pulled together by the force of me pulling on the chain) then I couldn't pull the chain near that much. It didn't appear to me that the chain had enough slop to skip teeth. But then again, that was the first time I've ever taken apart a transfer case so I don't know.

jneary said:

make sur all the tires are the same size and air pressure is critical with that t-case

Click to expand...

They need to be the same brand as well - in other words, no mixing and matching manufacturers or models.

Got good ATF in the t-case?

Jim www.yuccaman.com

Yucca-Man said:

They need to be the same brand as well - in other words, no mixing and matching manufacturers or models.

Got good ATF in the t-case?

Jim www.yuccaman.com

Click to expand...

All tires all the same brand, size, pressure. It really shouldn't be popping based on tire pressure.

ATF is Valvoline Synthetic ATF +4.