HI ALL. STILL WORKING ON THIS DRIVELINE ISSUE, AND HOPEFULLY SOMEONE WITH MORE KNOWLEDGE THAN I ( LIKE EVERYONE HERE) CAN GIVE ME THEIR 2 CENTS.
I HAVE A 201O MOUNTAIN UNLIMITED JK WITH AUTO TRANS AND JUST OVER 9K ON IT. MY BULLY DOG TUNER IS CURRENTLY SET TO FACTORY, AND IT IS SHOWING THAT MY TC LOCKS IN 4TH GEAR DOWN THE HIGHWAY IN TWO WHEEL DRIVE. IS THIS CORRECT OR DO I HAVE A TRANS CASE ISSUE? I'VE BEEN TRYING TO DIAGNOSE A DRIVELINE VIBRATION, DRAG, AND LOSS OF FUEL ECONOMY FOR SOME TIME, AND AFTER ELIMINATING ALL OTHER OPTIONS, THIS IS ALL I HAVE LEFT. THE DEALERSHIP IS BASICALLY NO HELP, VERY LAZY WHEN I COMES TO DIAGNOSTICS, SO I AM HOPING I WILL HAVE SOME INFO TO THROW AT THEM WHEN I TAKE IT IN AND DEMAND THAT THEY FIX IT.
ANY HELP IS MUCH APPRECIATED.

 

I'm really confused at what you're asking?

Are you saying that the transmission is locked in 4th gear and won't die shift going down the highway? While in 2 wheel drive?

Or us your transfer case locked into 2 wheel drive and won't go into 4 wheel drive?

 

i'm really not sure. the bully dog says "4th" and then underneath it, it says "tc locked" I can't find anything online regarding this reading with the tuner, nor anything as it pertains to my jeep, and so I am hoping that somebody knows what it means, because I sure dont. I can drop it into 4hi, and it feels the same as it does in 2wd, although I have not tried to make a uturn to check the radius difference. I just didn't know if it was supposed to read "tc locked" or not.

 

Your ok....that is your torque converter locking and unlocking. That is normal for an auto trans, I have a bully dog and I know exactly what your talking about, the bd just displaying when it locks. Without getting into alot of detail your tc creates a solid link between your engine and the auto trans just know that it is normal to be locking and unlocking

 

thanks for the info. i've had so many issues with this thing. I'm about to drive it into the river, and see if it makes a better boat, than a suv.

 

Just a quick question: When I jack up the front end of my jeep, and put it on stands, when I spin my one of my tires, about how far should it continue to rotate after I stop applying force to it? Keep in mind, although I am not weak, I am a smaller woman, so I'm not shooting it around there with the force that a man would. Mine only continues to spin about a 1/4 turn before it stops and I have regreased the caliper pins and bled the brakes in the front. Still spins very little with the front axle disengaged and the brake calipers removed. My friend has a tundra 4wd, and said his goes around about 2 1/2 times. Does it sound like a problem in the front diff, or would the gravelly vibration more likely be coming from the back? I can feel it in the steering wheel, floorboard, and seat (bottom and back) when going down the highway.
thanks

 

How many miles are on your jeep? What model (rubicon, Sahara, x)? Edit: just looked at the OP and say you have a mountain edition.

You have to keep in mind, the the brake pads will always rub the rotor, by design. Also your spinning the front axle, differential, other side axle, and hub, when your doing your spin test, and that's all sealed in the axle. That's a lot more resistance.

Your original problem is vibration it sounds? Here's my opinion. If it is speed dependent, the it is most likely a tire out if balance. Try rotating the front tires to the back and see if the shimmy in the steering wheel goes away.

If the vibration is all the time, I would check all the torques on your suspension components and make sure everything is snug. Follow plan mans "death wobble" thread, it will walk you through that.

If that doesn't work, check your driveline (driveshafts) and ball joints for wear or damage.

That's the best I can give you from estimation.

 

My understanding of your complaint of a gravely sound may be a bad wheel bearing. Does the pitch of the sound rise and fall with increase and decrease of speed? If so you can possibly determine which side it is on by slightly weaving down a straight lane of highway so that the weight of the vehicle is shifted from one side to the other. If it is a rumbly wheel bearing it should make more noise when the weight is shifted to that side.

 

X2 I'm thinking this may be the culprit as well.
Also get a good look at your front and rear drive shafts, where they connect to the transmission and at the axles...look for little rubber boots near the U joints and see if any are torn or if you see what looks to be like grease splatter around the body near the drive shaft ends...if you don't have a bad wheel bearing you may have a torn boot and now from crap getting in there it may be a bad U joint? thinking??
Between jkred's suggestion and pushrod's advice I think you'll find the cause

 

sorry it took so long to respond. I was out of town, in the boonies where there is no internet,.. can you imagine?
Anyway, I have checked both drive shafts and they look perfect, no torn boots, grease, lost weights, etc.
The irritation really isn't a sound, more than an actual vibration that I feel. I have tried the weaving down a straight road, and I get no sound at all, other than what I would assume these crappy oem tires that keep going out of balance. It seems that the vibration started right after I installed the new adj. lower frt control arms to address the flighty steering from the 2" lift ( I'm a short girl, so cut me some slack_) but I have adjusted them several times, and once replaced the stock arms, but the vibrations are still there.
I retorqued everything underneath, with a torque wrench, and a cheater bar, until i nearly filled my undies. Still the same.
I am just starting to think that maybe it's just these shitty tires, and maybe this is a good excuse to get some bigger feet underneath my girl. How big of a tire can I put on this thing with a 2" puck lift, and no gear alterations, without making it useless for daily driving?
It is a 2010 unlimited jk mountaiin edition x with a sport package, automatic tranny, 9 thousand, very pampered miles. She has only seen maybe two gravel roads. Not because I don't want to play, I just work too damn much.
thanks guys. what do ya think?