rear end noise ?
Thread Starter
Instructor
Joined: Jun 2004
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From: 1987- L98, auto OH
rear end noise ?
I know that it's probably annoying to try to diagnose something by someone trying to describe a sound, but I'd appreciate being pointed in the right direction. I have a strange sound that has appeared coming from the rear of my 1987 Vette. It is not consistent, but appears to make itself known at about 35 MPH and above, but not all the time. It has a sort of womp, whomp, whomp sort of sound, like some rotating part is encountering some problem as the part rotates to a certain spot. I am wondering if this may be a common sound associated with a rear wheel bearing starting to go??? I am praying that it is not in the Dana rear end as I can see dollar signs flying out of the window. Can a bad rear u-joint make this kind of sound? As I said, sometimes it is absolutely quiet, at others I can hear it as long as the interior noise level is light to moderate. Unless I want to turn up the radio and ignore it, I guess I need to find out what this is. Thanks for any help!
Brad
PS- If it helps any, this car has only 49,000 on it and was stored every winter. Wonder if sitting in one place for so long could hurt the bearings with the weight sitting on one spot for so long?
Brad
PS- If it helps any, this car has only 49,000 on it and was stored every winter. Wonder if sitting in one place for so long could hurt the bearings with the weight sitting on one spot for so long?
Team Owner
Joined: Sep 2001
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From: Athens AL
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U-joints would make their presence felt in gear shifts and from stop/starts.
That noise is probably the bearing, in which case you should replace the U-joints anyway. Jack up the rear and grab the wheel at 12-6 and try to wiggle it, it shouldnt move.
That noise is probably the bearing, in which case you should replace the U-joints anyway. Jack up the rear and grab the wheel at 12-6 and try to wiggle it, it shouldnt move.
Thread Starter
Instructor
Joined: Jun 2004
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From: 1987- L98, auto OH
Thanks Vader. I'll try that tip. Hopefully it's just the bearing and not some internal problem with the Dana rearend. The bearing I can handle, the rear... that's a little scary!
Brad
Brad
Team Owner
Joined: Mar 2000
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From: Boston, MA
Does the noise happen in both acceleration and overrun? In other words if it is making the noise while on the gas some does it make the same noise if you let off the gas and start slowing down? Is it definitely MPH related and not RPM? Does the back end feel "twitchy" at all? Normall you'd feel this more at highway speeds.
Thread Starter
Instructor
Joined: Jun 2004
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From: 1987- L98, auto OH
No twitchiness at all from the rear. I did notice that once when it was making the noise that if I backed off the throttle a bit, the noise seemed to go away. It came back when I put the power back on, but this only happened once so far. Really bizzare symptoms.
Brad
Brad
Thread Starter
Instructor
Joined: Jun 2004
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From: 1987- L98, auto OH
Yeah, it sure does sound like a u-joint, doesn't it? Wish it was a repeatable event, but not so far. I did jack up the passenger side rear (where the noise appears to be coming from). I was unable to get any movement when trying to twist the tire from the 3 and 9 o'clock positions or when pulling straight in and out on the tire at the 12 and 6 o'clock positions. If I grab it at the 6 and 12 positions and try to rock the rear tire (in at the top, out on the bottom and reversing that operation repeatedly), there is some movement. I believe that this is what Vader said should not happen. There is not much movement, but I can feel some play here. Sound like a rear bearing starting to wear to anyone? Thanks for all the help on this mystery.
Brad
PS- Anyone know how difficult it is to change out the u-joints on the drive axels? It appears that the main drive shaft u-joints will require dropping the exhaust system.
Brad
PS- Anyone know how difficult it is to change out the u-joints on the drive axels? It appears that the main drive shaft u-joints will require dropping the exhaust system.
