Got a bit of a peculiar issue with my car… Long post, I know, but bear with me please. It all has details pertaining to my problem.
What it is, is a sound that is coming from somewhere in my drive train, and almost sounds like it is directly under me when I’m driving. I typically only hear it on decal, but I know it is present at all times because I can hear it when going under overpasses and such. It is a metal on metal sound that I would compare to, for example, you know when kids stick playing cards in the spokes of their bicycles? It’s like that, only metal on metal. I’m not sure if I would call it a tick or a clunk. It speeds up and slows down based on, it seems to me, the vehicle’s speed, not the engines rpm. It has been getting increasingly louder and louder as time has worn on.
Originally I thought there might be something wrong internally in the transmission. However, now I’m almost sure it is the driveshaft, and here is why…
I took an hour one evening last week, jacked the up the rear of the car and removed the driveshaft. I examined the splines, both on the driveshaft and the transmission and they both looked fine. U-joints were still in good shape; I replaced them maybe a year ago. The transmission was fine, still shifts beautifully through all gears and I could feel gear mesh in both directions while playing with the tail-shaft, no binding. The rear end was also very tight, felt great. So, I started the car and ran it up through the gears (driveshaft still removed)… the sound was not present.
Following this, I re-installed the driveshaft and ran the car up through the gears with the rear end still elevated. The sound had returned. I popped the clutch and just let the tires spin free at idle, about 800rpm, and the sound was constant. I crawled under the car during this time and the sound is coming directly from the center of the driveshaft. You could move away from the center of the driveshaft in either direction and the sound would get fainter.
There were no visible marks on the driveshaft as far as it might be rubbing anything. No weights were knocked off of it. Nothing.
Also after parking the car one evening last week and shutting it off, I heard a scraping type noise coming from underneath the vehicle. I looked under the car, the driveshaft wasn’t spinning but the sound was coming directly from where the driveshaft is. It sounded as if there was something in it that was still in motion and rubbing the inside walls of the driveshaft.
So my question is this: Is there something that runs down the center of the driveshaft, i.e. is it not hollow? Is there like a torque tube in it or something? Because it seems like there is a shaft inside of it that has broken and is what is making the noise.
Either that or has anyone experienced this before, or something similar? Any ideas whatsoever on what this could be?
Thanks guys.
What it is, is a sound that is coming from somewhere in my drive train, and almost sounds like it is directly under me when I’m driving. I typically only hear it on decal, but I know it is present at all times because I can hear it when going under overpasses and such. It is a metal on metal sound that I would compare to, for example, you know when kids stick playing cards in the spokes of their bicycles? It’s like that, only metal on metal. I’m not sure if I would call it a tick or a clunk. It speeds up and slows down based on, it seems to me, the vehicle’s speed, not the engines rpm. It has been getting increasingly louder and louder as time has worn on.
Originally I thought there might be something wrong internally in the transmission. However, now I’m almost sure it is the driveshaft, and here is why…
I took an hour one evening last week, jacked the up the rear of the car and removed the driveshaft. I examined the splines, both on the driveshaft and the transmission and they both looked fine. U-joints were still in good shape; I replaced them maybe a year ago. The transmission was fine, still shifts beautifully through all gears and I could feel gear mesh in both directions while playing with the tail-shaft, no binding. The rear end was also very tight, felt great. So, I started the car and ran it up through the gears (driveshaft still removed)… the sound was not present.
Following this, I re-installed the driveshaft and ran the car up through the gears with the rear end still elevated. The sound had returned. I popped the clutch and just let the tires spin free at idle, about 800rpm, and the sound was constant. I crawled under the car during this time and the sound is coming directly from the center of the driveshaft. You could move away from the center of the driveshaft in either direction and the sound would get fainter.
There were no visible marks on the driveshaft as far as it might be rubbing anything. No weights were knocked off of it. Nothing.
Also after parking the car one evening last week and shutting it off, I heard a scraping type noise coming from underneath the vehicle. I looked under the car, the driveshaft wasn’t spinning but the sound was coming directly from where the driveshaft is. It sounded as if there was something in it that was still in motion and rubbing the inside walls of the driveshaft.
So my question is this: Is there something that runs down the center of the driveshaft, i.e. is it not hollow? Is there like a torque tube in it or something? Because it seems like there is a shaft inside of it that has broken and is what is making the noise.
Either that or has anyone experienced this before, or something similar? Any ideas whatsoever on what this could be?
Thanks guys.
