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.
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.