So when I went to pick up my truck, the mechanic told me I didn't actually have to replace the differential, it might just be the pinion bearing or something not actually deep inside there. Guess I am off to search about loose pinion bearings....

 

so, i read the thread and i too thought that it was coming from the front of the truck--so i put down me back seats and really paid attention (cost me $20 to do that..). Needless to say i will be dropping the Diff cover and checking it out. Crap--thought that it was the tires originally--then i read the threads and---we will see--anybody else have any advice on what to look out for??

 

I spent the weekend down in New Orleans, woohoo, (First night of Harrah's reopening) so I didn't get a chance until today to drop the rear drive shaft and take the rig for a spin. Guess what, the noise is STILL there! I knew it was coming from the front. So I jacked her up and got her to 52mph, the speed where the sound is the loudest, and what do you know? The front bumper is vibrating like crazy. So to me that seems, like it is going to be the front diff, wheel bearings or maybe CV axles. Anyone had an experience like this before?

 

The noise has moved around quite a bit in the thread.

You might still try what I mentioned and see if that helps (also try to find a mechanic with a chassis microphone so you can pinpoint the location of the noise more precisely while actually driving).

 

Alright, I think I will do what you say Jamie. I have a feeling it might be the wheel bearings with how much the front was vibrating. I will let ya'll know who ends up being right though!

 

stick it in hi-4 off pavement and turn the wheel while going slowly -- under 10 mph -- with your windows down. is the noise not a roar but rather a sick-sounding fast tapping? if so, i'm gonna still say one or both of your CVs are shot. you said way up top that they had a lot of droop. they shouldn't have that. they don't have to be leaking grease or have torn boots for them to be hosed up. i'd bet that once you have it/them out, and you hold them up by one end, you could bounce them up and down like there's a spring in there (btw there isn't). sounds like they simply have way too much play, and it's just a matter of time before they really blow.

 

Did you suggest to do this test off pavement for the sake of not hurting the drivetrain or because it is necessary to hear the clicking/popping? I just did some sharp turns while in FWD (dropped rear driveshaft) and heard no popping whatsoever. This was on the street though. I won't be able to find a place to do it off road until this afternoon. Also, with ADD, it is not possible to take the CV joints out and drive around is it?

 

I dont know where i possible stand on all this but--drained the oil last night didnt really see too much metal attached to the bottom drain plug magnet. However, when i jacked up the rear end and put it in gear--it wasnt exactly silent and had a shisssshhhhh kinda noise to it. There are also sometimes when the rearend feels like it clunks every-so-slightly. But again i also have the same whining/hum once i reach ~30-50 mph. Will try those things you guys talked about. But the last question--would there be more metal fragments in the oil as an indicator? I know this has been addressed before......

 

hross, you never said if you thought the noise was coming from the front or the back after you rode in the back. I think your problem is probably in the driveshaft somewhere rather than the Diff. I had my fluids changed a few days ago and there was a good bit of metal in the diffs but probably nothing to worry about.

Back to my problem, I will now bet money that it is the Driver's side CV or the front differential. I jacked it up again today during my lunch break and ran the front tires up to 52mph. Lot's of vibration. At lower speeds I can see the CV wobbling more than the one on the opposite side.

I then cut her off and started pushing/pulling on both CVs. The driver's side CV has a HECK of a lot more play where it goes into the diff than the one on the opposite side.

Does anyone think I should be looking at replacing the CV or is there something wrong with the differential?

 

DOes the rattle inside your truck sound anything like the sound clips I posted a few days ago? In this thread.

 

I am sorry but it sounds nothing like the rattle you are hearing. Mine sounds more like a droning. That was a good idea recording with your MP3 player though. I am gonna try that and put it on here just so ya'll can get a better feel for the sound I am dealing with.


Right now I am looking at a diagram of the differential and it shows a snap ring that goes between the CV and the diff. Could it be that this "snap ring" has broken on me? I don't know what it does but it is in the right place to possibly be causing the problem.

 

Well, i grabbed my CV's and they are tight--checked out the driveshaft and it is tight. The noise ounds more like a droning in the front and a whine outback. Screw it--i am just going to rebuild the rearend with a True Trac and while in the process have the driveshaft checked out. Anybody have a V6/Turbo diff they would like to get rid of. Thanks for the help though guys--Any suggestions on getting a better rebuild i.e. stronger gears etc...Vendors you recommend?

 

Do I have to be in 4WD to hear the popping/clicking with ADD? This morning I noticed a single POP noise while turning in to park. Might this be a sign of of a bad CV?


UPDATE: Went out to smoke a cigarette and looked underneath while I was outside. I just saw for the first time that oil/lube is leaking from where the CV connects to the differential on the side where I believe the noise is coming from...

 

Replaced driver's side CV last night. Lots better. Most of the vibration on braking went away. Much quieter in the cabin. Noise is still there, I suspect it's the pass CV. Will do that one this weekend.

Sustained one injury. I got ready to yam on that spindle nut with my breaker bar because of the 174ft/lbs it is supposed to be torqued to. As I leaned my weight on to the bar, the nut broke free and I fell to the floor and scraped my elbow. I could have loosened the nut with two fingers. That is not good right?

My old axle seemed pretty worn out. So if you have an older truck and some vibration on braking and a low roaring sound, could possibly be your CVs.

I used the CV writeup on 4x4wire.com, it was pretty darn helpful. Thanks for your help suggestions all!