np242 - serious help needed

i need some serious help guys! the other day i was out offroading, 4lo didn't engage all the way and the gears were kind of clackin against each other. got it into gear everything seemed good. while doing my brakes last weekend i got under there, put the tranny in neutral and the tcase in 4 hi while it was in the air and turned the ds by hand to see if everything was turning alright inside and i heard a noise that sounded like a marble rolling around in there.

then this week it rained good here at school and we went out to get some food. gave it a little too much gas and the tires went a spinning. i put it into 4 fulltime and drove like that instead. i get back to school and take it out of 4wd and back into 2, except now when i stomp on the gas the tires no longer spin and there is a clunking noise from underneath.

took it to the dealership so they could figure out what is going on. they don't know yet and when i showed them the ds thing i tried, i noticed that it felt different than when i was under there this weekend. we think maybe a stretched chain or something. anyone else have any insight?????

-jeeper in need!

tires don't spin because it's still in full time - it's spline locked.

http://www.rsgear.com/troubleNV242.htm

crawldaddy said:

tires don't spin because it's still in full time - it's spline locked.

http://www.rsgear.com/troubleNV242.htm

Click to expand...

I'm a little concerned about the following:

www.rsgear.com/troubleNV242.htm said:

6. Many states now require dynamic emissions tests on dynamometer. This unit cannot be tested on a dyno without immediate failure to the internal transfer case differential. If this unit is used on a dyno with the front wheels stationary, the internal differential pinions will rotate at approximately 15,000 RPM. This immediately wipes out the differential and causes other internal damage to the transfer case. The same thing will happen if the vehicle is towed with the front wheels on a dolly. Make sure to note this on your work order and make sure the customer signs acknowledging that there is no warranty for this type of failure.

Click to expand...

Seems to me that if the case is in 2WD, it shouldn't be affected. Can anyone shed some light on this? I've got to go in for smog later this year and would like one more thing to add to the list of explanations (currently standing at, "yes, it's a federal-emissions vehicle approved for California...").

when the link says the case will fail if used on a dyno with front tires on the ground does it mean if its in full-time when this happens? or just it will fail period? cause we have to get dyno emmisions in GA and that'd be vital information to have.

The claim at the site I referenced seems plausible, but alarmist. I will try to remember to call them and ask why....in detail.

I checked the smogcheck site in CA, and they don't list the XJ as a vehicle that can not be tested on the single-axle dynamometer, and I believe more than one of mine has been tested that way. Interestingly, my Suzuki was not tested on the dyno.

Dyno testing is not the same as towing, but the owner's manual does mention that towing with one axle raised must be limited to less than 30 mph and less than 15 miles.

that would be great if you could call for more info...

whats with all the 242 posts lately, 3 in the past week or so... i never see anything on 242's

they were probably mostly me haha. i've been freakin out, we'll have to see what it looks like in there when i bust it open...

I've been thinking about the RSgear claims of spline locking and dyno's tearing-up gear sets. I think it's all horse pucky.

First of all, with a diff in each axle, and another one in the tcase, each tire could be a different diameter, and nothing bad would happen...that's what a diff is all about...so their noise about measuring tire diameters is just a bunch of schmegma (are words like that allowed on this site?).

Second, the 2WD setting is a full disconnect on the front axle. I've spoken to a lead mechanic, a t-case rebuilder, and two smog techs. They all say there's nothing bad that will happen to a 242 if you dyno test with the front wheels not moving. They also said that they suspected the t-case would not like being in FT4 during such a test. I conclude that the stuff on the RSgear web site is a copy/paste from a quadra-trac case.

Let me hear what you find inside there...one of mine is doing the same thing.

i didnt think 242 front axles did disconnect, at least they dont have a vacuum disconnect. but you're right abuot it sounding like its been copy pasted from elsewhere.

I'm not sure were the clip of the warning came from, but it might have been from a dodge dakota or darago, or for a Hummer, they have 242 in them too, but they are different in that they do not have a 2wd option. This will not be a problem in a Jeep 242.

Haven't seen this on our pre OBD2 XJ's and I don't think this could be a problem on a Durango since they should all be OBD2 as well (well, atleast here in Illinois, OBD2 cars don't get dyno'd). Now if there were any gas powered H1's that aren't ODB2, that could be a problem.

XJJack said:

I'm not sure were the clip of the warning came from, but it might have been from a dodge dakota or durago, or for a Hummer, they have 242 in them too, but they are different in that they do not have a 2wd option. This will not be a problem in a Jeep 242.

Click to expand...

It would be a problem if the TC is in any other position besides 2HI.
My understanding is that the TC differential is almost stationary when moving straight with identical tires in 4FT.
It starts turning and differentiating when the rear is not turning at the same rpms as the front. In a dyno scenario where only the rear turns, the differential will go bananas trying to send everything to the rear and could possibly overspeed. If I had to dyno my HJ I'd do it in 2HI. I think that the manual says to tow it with the TC in N.

falcon556 said:

It would be a problem if the TC is in any other position besides 2HI.
My understanding is that the TC differential is almost stationary when moving straight with identical tires in 4FT.
It starts turning and differentiating when the rear is not turning at the same rpms as the front. In a dyno scenario where only the rear turns, the differential will go bananas trying to send everything to the rear and could possibly overspeed. If I had to dyno my HJ I'd do it in 2HI. I think that the manual says to tow it with the TC in N.

Click to expand...

BINGO.....