okay to start off i just bought a 99 GC lardo 4.0 selec-trac two weeks ago and i came with rip boots in the fronts and a grinding sounds from the front .

So i thought it was the rip boots so i went ahead and got the impact wrench out and went to work, replace them and still grinding noise .. It will only grind when i shift it into 4wd,lo,hi. When it is in 2wd mode i dont hear anything.
I dont think it is the wheel hub assy from reading on here since it only does it in 4wd .

If its low on diff oil would it make that noise? or i was thinking it might be coming with the front diff also not really sure never owned anything 4wd before.....i tired to use the search but cant seem to find one with the same problems as mines...thanks

 

worn out u-joint maybe? check the fluid level in the diffs its pretty easy

 

I don't think the universal would do it, usually you get a vibration or thump with a universal, it could be the front gears or the transfer. Does the noise increase with speed or when you're wheel is cut all the way left or right?

BTW, Im new to this particular forum and cant figure out for the life of me how to Post my own topic? HELP

 

i'll try to check out this weekend since its suppose to be nice out..i hope i know where to look for the levels...

 

i'm not sure about the noise cutting in or out it just comes on right after the 4wd engages ... i hope i didnt get a lemon ,...it ifs a cheap and easy fix i wont be that man

 

All the info you'll need to repair the problems are online if you have the time and aren't dont desperately need the vehicle. Im new on this forum, but group XJ cherokees on Yahoo has been really good to me. Also as far as repairs, the Petersen's 4Wheel website has an archive of info on rebuilding things like transmissions and transfer cases. Also, being careful while doing this, if you lift all four wheels off the ground with stands on a solid surface U can run the Jeep in gear and see where the noise is coming from. I usually get my GF to sit in it to turn the wheel and for safety. Once you can be under the vehicle while its running every thing becomes much clearer. BUT BE SAFE, dont do this on soft uneven ground, try to do it lifting the axles not the body that way U can see the problem at working ride hight.

Also try 4H and 4L, I'm guessing you're transfer case needs some work, because the dill berry B4 U didnt read the manual on how to PROPERLY put it into 4wd. If you dont have the confidence to do the repair your self after you've read up on it, you can at least remove the problem part yourself from the Jeep and take it in for repair, this will save U butt loads of cash. Find a GOOD local mechanic to diagnose the problem and let him know you aint a rich man, then tell him you'll bring the part to him for repair.

 

OH, could be the CV to I've had that too.

 

there will either be a bolt or a small plastic cap, you pull that out and shine a light in. the fluid should be level with the hole..... i had a bad grinding noise on mine when it was in 4 wheel drive, it made me cringe it was so bad. it was just a ujoint. it didnt at first but like xjluke was saying it did vibrate shortly after

 

I know this may sound stupid but I also just bought one thats 4x4 and was doing the same thing...i look under it and it has not drive shaft in it...did u check to see that urs does? I was told some ppl take them out in the summer to help with gas and so they dont get messed up....just a thought to check

 

been dealing with the same problem for 3 weeks on mine.i have changed transfer case,front diff,front driveshaft,still having the same problem.

 

going to check all those this weekend . i'll keep you guys updated .

 

thats what i dont want to end up doing is replace every single parts. but then again i bought it used who knows when the gear oil was last changed

 

**update**

change my oil for my front diffs and transfer case.

the front diff oils was milky silver and thick so i'm not sure if that was the problem i was having. The transfer case was still red and smooth , so i'm guess that its still good. There seems to be leaking fluid from the front diff and transfer case that runs the botttoms of the case. But now it seem like i hear scraping like a brake sheild rubing agaisnt the rotor. going to look at that when i get a chance to but a 3ton jack since i only got 1 1/2 ton

thanks for all the good info guys , you guys rock!!

 

well brought the jeep ice fishing today and put her in 4wd mode and i hear the grinding again grrrr...it sounds like its coming from the front diff...what can it can causeing it from the front diff?

 

Often noises sound like there coming from else where. I'm telling U lift the whole thing get under and you'll find the prob in no time. Also correct me if I'm wrong but if it were the front diff you'd hear it all the time because its always working just not engaged when not in 4wd. Did U try 4wd low? Did U try seeing if it was louder or more quiet when you had the wheel cut extreme left or right. BTW you should generally really try to avoid cutting you're wheel to the extremes when in 4wd, your U joints dont like it under power and that how you blow them out. Its even worse if U do it on dry pavement because the wheels aren't allowed to slip.