Hello Folks.
Not sure if anyone can help..but I am in the process of trying to track down a bad grinding noise accompanied by vibration.
Vehical Info: 02 Chevy Tracker ZR2 2 door 4WD. 2.0 engine with auto trans.
I have replaced both rear axle bearings thinking this was my problem. After realizing it was not I did some trouble shooting (what I should have done from the start). Here is what I know.
The grinding shows up on the highway when vehical speed reaches around 45MPH and will keep grinding / vibrating untill I come to a stop. It sounds like a bearing that has reached a speed to where it becomes unstable and then is rattling like crazy. I can recreat this noise by putting the vehical up on jackstands and running it. I checked drive shafts and U-Joints and they are good. I then went through a series of tests up on stands.
Ran it in 2WD and sure enough grinding shows up around 40MPH and stays on until i slow way down. Putting it in 4WD high results in the same thing.
I put the trans in Drive, but put the trabsfer case in Neutral....rev it up good...no grinding..seems smooth. I would assume then that the noise is coming from somewhere after the input side of the transfer case to the rear axles. Since I am sure its not rear axle bearings or driveshafts, maybe rear end. I used a mechanics steathascope and listned to the rear axle when a friend got the grinding noise to show up. I could hear it in the rear end. I then went to listen to the transfer case and it was about 30 times louder.....definatly close to the transfer case.
I have since removed the transfer case to see if I could open it up and find a bad bearing. To me it sounds a little "rattleish" inside. I know there is some play inside, but just doesnt sound right to me somehow. When I removed the trabnsfer case I wiggled the output shaft of the tranny and it seems very loose. Is this normal? I posted a couple videos of the transfer case noise and rear output shaft.
Any insight or if anyone has seen this, please let me know.
No worse then when you dump a rear end. Some very very fines....but no chunks...
I am now debating weather to buy a used transfercase from a salvage place locally (prices here are about $200) or open it up and start replacing gears, chains, etc. The vehical has 188K miles on it.
Well, finished opening up the transfer case and snooping around inside. I didn't see anything obviouse, although I am not really sure what to look for. I was keeping an eye open for broken gears, bearings that look destryoed, etc but nothing obviouse. I have not taken the input shaft and associated "stuff" off it yet. I suspect there is a bearing in the middle somewhere that is no good. I did buy the used transfer case as I am pretty sure its a transfer case problem. I'll install it and see what happens. If its not this I am out of ideas. I'll post my progress incase anyone else reads this in the future and wants to know the end result..
Ok.. I can include the transfer case not being the problem. And here I thought I logically troubleshooted the problem...apparently not. So, Its not transfer case, Not wheel bearings. I am left with rear driveshaft and u joints (which are new by the look and feel of them, but could be a balance issue?), and transmission. This POS may end up in the scrap yard for crushing in a couple weeks...very frustrating. I have taken a video of the sound when its running and will uploda it to my youtube account and if anyones got any ideas I am all ears....
its a one piece driveshaft both front and rear (mines a 2 door, maybe 4 door is two piece?) U joints on rear shaft are new, I can tell by looking at them. Probably done very recently, but was done by a hack. I noticed they tack welded the retaining clips in for some reason(very small tacks). I also noticed that they used greasable u-joints. I am wondering if this was done correctly after looking at it in detail. I noticed that the zerks are timed 90 degrees front to back..I would have thought it would be 180. could a severly unbalanced driveshaft make that racket? I just bought it (as-is) and upon test drive was ok. Infact this didnt show up untill about 50km of driving. There are no weights on the driveshaft...which I also find interesting. It looks as though there may be a spot where one was...but not sure. as for steathescop..I used a stick and held it to my ear. When placed onthe rear end you can hear / feel it ...when you put it on the trasnfer case you would swear it was inside....apprantly not.
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Grinding / Bad Bearing...
Linear Mode
