[AndrewF329]

I've noticed a clunking noise that sounds like it is somewhere in the front end. I am suspecting it is the differential because it gets worse with 4wd engaged. It is not grinding or whirring so I don't think its a bearing. It is tied to wheel speed and not engine rpm and is approximately the same frequency as the wheel rotation. The diff fluid is due to be replaced anyway so I plan to take care of it soon. I have never serviced a diff before, what should I look for to diagnose the noise?

2003 WJ 4.0L selec-trak 142k mi

 

[Delta0]

I've noticed a clunking noise that sounds like it is somewhere in the front end. I am suspecting it is the differential because it gets worse with 4wd engaged. It is not grinding or whirring so I don't think its a bearing. It is tied to wheel speed and not engine rpm and is approximately the same frequency as the wheel rotation. The diff fluid is due to be replaced anyway so I plan to take care of it soon. I have never serviced a diff before, what should I look for to diagnose the noise?

2003 WJ 4.0L selec-trak 142k mi

Drain your diff into a pan, and check for metal in the oil.

 

[WJ60]

Drain the diff fluid, pull the cover, and do a visual inspection. If it's the diff it will probably be pretty obvious.

 

[AndrewF329]

Thanks for the replies. I checked the fluid today and the level is fine and the fluid doesn't look too bad. I'll see what I find when I empty it later this week. Is there anything else to check besides the diff? I'm not that experienced as a mechanic but I'm an engineer so I have no problem working on my car, I just don't know what to look at.

 

[10kmistake]

I had a rattle at wheel speed, clunk when engaging, pop when turning and one heck of a vibration over 60MPH. Took out the front drive shaft and had zero of the issues. Mine turned out to be a bad u joint combined with a bad CV Centering Yoke. The previous owner had purchased the shaft online after a 3" IRO lift. (double cardan shaft)

 

[Delta0]

I had a rattle at wheel speed, clunk when engaging, pop when turning and one heck of a vibration over 60MPH. Took out the front drive shaft and had zero of the issues. Mine turned out to be a bad u joint combined with a bad CV Centering Yoke. The previous owner had purchased the shaft online after a 3" IRO lift. (double cardan shaft)

Thank you for copying us in.

 

[fxer82]

I've noticed a clunking noise that sounds like it is somewhere in the front end. I am suspecting it is the differential because it gets worse with 4wd engaged. It is not grinding or whirring so I don't think its a bearing. It is tied to wheel speed and not engine rpm and is approximately the same frequency as the wheel rotation. The diff fluid is due to be replaced anyway so I plan to take care of it soon. I have never serviced a diff before, what should I look for to diagnose the noise?

2003 WJ 4.0L selec-trak 142k mi

id check front lower and upper control arms first off with it off the ground by jacking it up and using jack stands. also wiggle the wheel top and bottom and side to side, grab ahold of steering rods see if you get any rotation of them, check shocks and all the front end parts before you truly diagnose what is making this noise. while up you can also check the u Joints and the pinion shaft movement up and down, in and out. lastly id grab ahold of the entire differenital casting and try to get any rotational movement. no i dont mean the axle i mean the differential casting itself. that should give you a good diagnose of what is or not giving you any noise...good luck and dont get the wrong person telling you what it needs when you can do at least the best diagnoses yourself. the others here on the changing the oil are correct and follow them when all outside the diff has been eliminated. there is a great bunch of people here that do help.

 

[Rod Kimble]

id check front lower and upper control arms first off with it off the ground by jacking it up and using jack stands. also wiggle the wheel top and bottom and side to side, grab ahold of steering rods see if you get any rotation of them, check shocks and all the front end parts before you truly diagnose what is making this noise. while up you can also check the u Joints and the pinion shaft movement up and down, in and out. lastly id grab ahold of the entire differenital casting and try to get any rotational movement. no i dont mean the axle i mean the differential casting itself. that should give you a good diagnose of what is or not giving you any noise...good luck and dont get the wrong person telling you what it needs when you can do at least the best diagnoses yourself. the others here on the changing the oil are correct and follow them when all outside the diff has been eliminated. there is a great bunch of people here that do help.

Definitely Agree with fxer82 especially if you have a lift on the WJ definitely check that the lower control arms are secure. I also had a clunk and that was my issue...a bolt had come out of the bracket for my passenger side lower control arm

 

[Delta0]

id check front lower and upper control arms first off with it off the ground by jacking it up and using jack stands. also wiggle the wheel top and bottom and side to side, grab ahold of steering rods see if you get any rotation of them, Please will you explain that a bit Fx? check shocks and all the front end parts before you truly diagnose what is making this noise. while up you can also check the u Joints and the pinion shaft movement up and down, in and out. lastly id grab ahold of the entire differenital casting and try to get any rotational movement. no i dont mean the axle i mean the differential casting itself. that should give you a good diagnose of what is or not giving you any noise...good luck and dont get the wrong person telling you what it needs when you can do at least the best diagnoses yourself. the others here on the changing the oil are correct and follow them when all outside the diff has been eliminated. there is a great bunch of people here that do help.

 

[fxer82]

all rods going from one side to the other side that hook up to the wheels housings. there should be no rotation they should be tight without any rotation there is a bit of 1/16" of movement but not loose. meaning get a hold of one and try to spin it in place there should be very little spin or rotation with any rods. there is a SERVICE MANUAL on a site that you can download for free to your computer just can't print it out without paying for it. it is NOT a haynes manual it a factory service manual....has all the years and all the different engines, differentials, transmissions, electrical, electrical connectors...all i did was duckduckgo searched manuals for jeep WJ or jeep grand cherokee wj and i had to look for it can't remember which site i got it from. i tried to post a copy to this forum but it is to large and wouldn't allow it to download.

 

[Delta0]

all rods going from one side to the other side that hook up to the wheels housings. there should be no rotation they should be tight without any rotation there is a bit of 1/16" of movement but not loose. meaning get a hold of one and try to spin it in place there should be very little spin or rotation with any rods. there is a SERVICE MANUAL on a site that you can download for free to your computer just can't print it out without paying for it. it is NOT a haynes manual it a factory service manual....has all the years and all the different engines, differentials, transmissions, electrical, electrical connectors...all i did was duckduckgo searched manuals for jeep WJ or jeep grand cherokee wj and i had to look for it can't remember which site i got it from. i tried to post a copy to this forum but it is to large and wouldn't allow it to download.

Thanks Fx.

Have you tried posting one chapter of the manual at a time?

 

[vol961]

Sounds like CV axle to me.

But easy to check where noise is coming from: Jack up all 4 wheels, put on jack stands with tires clearly off the ground.
Start the engine, put in drive, hop out of the jeep and listen for the sound with the engine idling and all 4 wheels turning.

Take the wheels off if you need closer access to axles, bearings etc

May sound scary but I do it all the time when necessary.

 

[Delta0]

Sounds like CV axle to me.

But easy to check where noise is coming from: Jack up all 4 wheels, put on jack stands with tires clearly off the ground.
Start the engine, put in drive, hop out of the jeep and listen for the sound with the engine idling and all 4 wheels turning.

Take the wheels off if you need closer access to axles, bearings etc

May sound scary but I do it all the time when necessary.

Ventilation.

 

[AndrewF329]

Sorry to go dark on you guys, I had covid for awhile so I couldn't get any work done. I opened up the diff cover today and did a visual inspection and everything looks really clean and nice. Theres minimal wear and no broken or chipped teeth, and no metal in the bottom. Also when spinning the wheels there is minimal slop to the diff and everything feels smooth.

Spoiler: Picture

id check front lower and upper control arms first off with it off the ground by jacking it up and using jack stands. also wiggle the wheel top and bottom and side to side, grab ahold of steering rods see if you get any rotation of them, check shocks and all the front end parts before you truly diagnose what is making this noise. while up you can also check the u Joints and the pinion shaft movement up and down, in and out. lastly id grab ahold of the entire differenital casting and try to get any rotational movement. no i dont mean the axle i mean the differential casting itself.

I checked all of the arms and rods and none of them are loose. I wiggled the wheels and they are nice and tight. The pinion shaft doesn't have any in and out movement but there is a fair bit of rotational slop from the transfer case, I took a video of rotating both shafts on the T case.

Spoiler: Video

Sounds like CV axle to me.

But easy to check where noise is coming from: Jack up all 4 wheels, put on jack stands with tires clearly off the ground.
Start the engine, put in drive, hop out of the jeep and listen for the sound with the engine idling and all 4 wheels turning.

I checked the CV as much as I could without disassembly and didn't notice anything. Unfortunately I don't have enough jack stands or anything else to prop it up so I couldn't try that.

 

[AndrewF329]

Ok so I solved the issue. Turns out the front drive shaft's front universal was shot. Unfortunately you can't repair these too easily so the whole drive shaft had to be replaced. Once it was swapped, smooth as when I bought it! This is definitely a lesson in having the right tools for diagnosing the problem, I could've had this done months ago. I just ordered two more jack stands.

 

[HarryH3]

Driveshaft repairs can be done with hand tools. I've even done them on the roadside and on mountain trails when a u-joint has broken. Here's a video for future reference that shows how to repair both the Rzeppa and Double-Cardan type of joints found on WJ's: Driveshaft Refurb

 

[CraigMBAx]

Ok so I solved the issue. Turns out the front drive shaft's front universal was shot. Unfortunately you can't repair these too easily so the whole drive shaft had to be replaced. Once it was swapped, smooth as when I bought it! This is definitely a lesson in having the right tools for diagnosing the problem, I could've had this done months ago. I just ordered two more jack stands.

Front drive shaft or axle shaft?

In the future, there are shops around who only do drivelines all over the country.

It was almost the same money for me to buy the universals from Rock Auto than it was to have them do it, plus they straightened and balanced them as part of the deal.