Grinding sound in 4WD

Hi! I'm hoping someone can help me out. I have a 2004 Jeep Grand Cherokee Lorado. While I keep it in mint condition visually it has over 200,000 miles k. It but runs and looks great. I love it!! I've had to do a lot of mechanical work to keep it up. Engine rebuild, rear axle bearings and seals, rear diff. Rebuild etc. recently the car started making a horrendous grinding metal sound in 4 wheel drive. There was a lot of play in the front drive shaft so I replaced the front universal joint. It was still making the noise so I replaced the CV shaft. Still making the sound. While I had it apart I noticed the hub bearing was a little loose but didn't make any noise when i spun it so I didn't replace it. The car runs quiet and smooth in 2 wheel drive but when I shift into 4 wheel drive it sounds like I'm dragging steel garbage cans behind me!!! Any thoughs on what my problem us Would be greatly appreciated. Ken

 

Bad T case. Had same problem

 

I was afraid it was the transfer case but that's where the noise seems to be come ngmfrom. Is swapping out the transfer case with a good used one hard? It doesn't like too bad of a job?? Any suggestions? Thanks. Ken

 

It's a fairly easy job, as long as your tranny mount and cross member come off easily. Easier to drop t case and tranny down some to access top bolts and harness.

 

Rebuild kits and chains are cheap enough at Summit and there are some great videos of how to rebuild it on youtube. The only specialty tool you will need will be a snap ring pliers. An impact will make it easier to remove the output shaft nuts.

 

Thanks for all the responses! You guys are great! I located a used 84,000 mile case at a local junk yard for $175. I figure I'll buy that and swap them out and then maybe take a shot at rebuilding the old as a back up. Does that sound reasonable? Thanks again for the help!!

 

Sounds good all the way around. Your welcome.

 

Does the transfer case take standard 90W gear oil like a differential?

 

I use 90w in mine . But mi,e is old school

 

It should be atf

 

Yep. If you have an automatic tranny it should use the same fluid as the tranny, ATF.

 

Ok guys! Here's the deal. Nasty noise in 4 wheel drive. Sounds like gears it's coming from area of drivers side front. Sounds like gears grinding stones. Like a snapping metric sound. To me it sounds like gear stripping or not meshing or a few teeth missing on a gear. I replaced all universal joints, replaced front drivers side wheel bearing and hub, I put in a new drivers side CV joint and I replaced transfer case with a used salvage yard transfe case. Still making the same noise. I took the cover off of the front differential case. The oil looked clean. Didn't see any metal filings or pieces of metal. Spun the gears and carrier and it rotated smoothly with no obvious noise. Without a lift it is difficult for me to pin point the source of the noise. I'm going to try to scratch up two more jack stands and try to get all four wheels off the ground to see if I can pinpoint the source. I'm starting to think it could be a problem with one or more of the small differential gears. Maybe CV shaft splines stripping out in gear or possibly a busted or worn down gear. I'm going to the cover off again poke around some more. Does anyone know if it is possible to remove the small differential gears while the differential is still in the car axel. Is it a tough job? Thanks. Ken

 

You might first have someone else drive the jeep in 4WD while you walk outside of it and around it. Try to isolate the noise. It may only be duplicated with weight on the vehicle. You never know. Is your jeep solid axle or IFS. If IFS could it be the CV axles going out. If there is no junk in the diff I would think it's okay.

 

Not to sound stupid or insult, but how do the back side of your brake rotors and pads look? If they're chewed up that will also make horrific noise depending on the severity of them

 

The brakes and rotors look ok. It only make the grinding metal sound in 4 wheel drive. I replaced the CV axel on the drivers side but not pass side. It sure sounds like its coming from the drivers sued front but with steel axels I wonder if it could be pass side CV shaft. Maybe before I tear into differential I should mess around with that. It sure sounds like a universal joint (CV joint) tearing itself apart. It's a cyclical noise. Not constant but on and off as wheel rotates. Maybe I should take a look at pass side CV joint. I'm pretty good with cars but the 4 wheel drive stuff is new to me. I least now I know how to swap out a transfer case in a day. I'll save the one I pulled out as a spare. Any other suggestions, thoughts would be appreciate. Pretty frustrating for sure.

 

I thought of this same thing, but he did say that it only makes the noise in 4WD.

 

CV axles make cyclical grinds and bumps especially noticeable in turns.

 

I know but still best to rule everything out though.

 

Well, I replaced both front wheel bearings and hub, both CV axels and swapped out transfer case. Still making quite a racket in 4 wheel drive. It also makes a low noise in 2 wheel drive. Like a mild grinding noise. In 4 wheel drive it sounds like I'm crushing rocks. The only thing left for me to replace is differential spider gears. It sure sounds like its coming from wheel area but sound does travel well in steel. I did open the differential but it looked ok. No metal in oil. Ring and pinion looked oil. Does anyone know what front axel is in a 2004 Grand Cherokee Larado 6 cylinder? Dana 35 so I can check local availability of spider gears if I find mine trashed? Thank!

 

I found this related to the grinding noise: worth a try. Internet is all over the place on the grinding noise. Wish I could hear it in person.

"I also have a 2000 JGCL that started doing this same thing about 100 miles after getting the front dif fluid changed. They assured me that they put the friction additive in but when I challenged them on it they agreed to "put more in" for free. At first they tried to blame the noise it on the transfer case but I'm too stuborn for that because I know the noise was traveling down the front driveshaft which made it sound like the TC. After doing 2 figure eights in their parking lot the noise went away. If you didn't change the front dif fluid lately then you probably have a leaking axle seal and low or no front dif fluid. Oh, btw, "they" = dodge service department."

This quote possibly makes sense

"Is there an actuator on these that engages 4wd? Mine is doing the same thing kinda acts like it won't fully go into 4wd..."

Another "quote"

"My quadradrive would grind make a god awful noise . I changed both axles wheel bearings and driveshaft still made the noise . I noticed it did it in cold weather more. I figured out it was my transfercase .Recently i did a 242hd swap so i can have 2wd and 4wd and no more noise . But i went through the same thing thinking of swapping out the front axle and that was the way i was going to go . I found some on car-part.com that were decently priced . But i feel your pain of tracking down front end noises."

I can't imagine that you bought a bad T case, but it can happen. Some Junkyards give you 30days on a part. I like the idea of finding a selectable 2WD/4WD T case like the 231 out of a TJ. They are cheap enough. First I would go over the front diff with a fine tooth comb and check all the gears for breakage.