AWDGuy

I've recently started hearing a loud knocking noise when going from forward to reverse and vice versa.

Its loud and its coming from the driveshaft somewhere. i thought it was my engine mounts but I replaced those and the noise is still there. Car feels a lot better so know the mounts were on their way out for sure, but I want this noise gone.





Noise is coming from this area, when you push the driveshaft back and forth, you can hear the knock coming from that....almost right under the front seats.

dporto

Take a look at the Transmission mount... If not that, perhaps the universal joints (2) on either end of the Cardan shaft (less likely I think). Good luck

AWDGuy

Transmission mount near the middle is good. the noise isnt coming from that mount.

charlieaf92

I believe another member just resolved a noise being caused by a loose coolant tube - worth double checking yours.

When I first saw the thread title I thought 'cv joint' but since you say its coming from the center, that seems less likely. Do you have a GoPro by any chance? I'd be interesting to mount it under there and do a few start/stops to see if you can see something happening visually.

AWDGuy

The noise is coming from that shaft. Exactly where that bracket is.

There's a bushing there. I'm suspecting that bushing is done.

I think it's part # 99637505403

Device2

IPB.

dporto

Hmmm, is that bushing pressed in like the front transmission mount is? It looks like it, but I've never been up in there so I can't tell...

Device2

I believe it is Dporto, in the Illustrated Parts Breakdown image I also see the front of the drive Assembly has a carrier that has two smaller bushing inside the front carrier P/N: 9967503401 or updated P/N: 9P1399225 its the dog bone looking bracket too so it could be those also.

AWDGuy

Yup looking at the diagrams on auto Atlanta, I think you're correct

AWDGuy

Actually. ...that would be too much in front. The noise is more around the boot in that diagram that the front dog bone.

I think I need to repack the spline shaft with grease or something.

Device2

AWDGuy, good to see you isolated the knocking down to a particular area. Out of curiosity since everything is close together have you looked at the Cardan Drive Shaft to see if it could be worn at the connecting u-joints? Or also see forward and rear play in the shaft.

Billup

Sloppy U Joit would definitely make a clunk twisting in either which direction. If it sounds like it's coming from below I'd agree with checking the above.

AWDGuy

Changed engine mounts, re packed driveshaft with grease (no more noise) and put in a new Guibo since mine was cracked to hell.

drives a lot better, feels very solid but the knock is still there and I found it. I'm worried I need to open the transmission though.
Here is a youtube vid of it. Sorry for the ****ty quality.

https://youtu.be/N5gCNesLtuY
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AWDGuy

That's video of my car on the hoist. Our original assessment of the driveshaft making the noise when going from frwd to reverse was false. While packing the driveshaft and replacing the guibo quieted things down, that knock is definitely coming from the axle and still there. So when we pull the shaft towards the outside (towards the wheels) it makes that knocking noise.

AWDGuy

Mechanic thinks it's something inside the transmission/differential. If that's the case, looks like I am back to hover porsche status for a while...