19 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHKnocking noise going from forward to reverse and vice versa
Reported repair
Replace engine mounts, re packed driveshaft
Reported resolution
1
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that report a fix
1
1 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Reported fix · Original poster
Changed engine mounts, re packed driveshaft with grease (no more noise) and put in a new Guibo since mine was cracked to hell.
Knocking noise going from forward to reverse and vice versa
Read full discussion summary
Leading evidence: 'Replace engine mounts, re packed driveshaft' (1 discussions report resolution; 0 report an unsuccessful attempt). Across 1 matching discussions, The most frequently discussed action is 'Replace engine mounts, re packed driveshaft' (1 discussions). For that action, 1 discussions report a resolution and 0 report an unsuccessful attempt. The most frequently reported fix is 'Replace engine mounts, re packed driveshaft', supported by resolution reports in 1 discussions. These are forum reports and suggestions, not a confirmed diagnosis.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed · Original poster
i thought it was my engine mounts but I replaced those and the noise is still there.
Knocking noise going from forward to reverse and vice versa
Check above
Suggestion or failed attempt
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion
If it sounds like it's coming from below I'd agree with checking the above.
Knocking noise going from forward to reverse and vice versa
Replace guibo quieted things down
Suggestion or failed attempt
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that contain suggestions
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Suggestion · Original poster
While packing the driveshaft and replacing the guibo quieted things down, that knock is definitely coming from the axle and still there.
Knocking noise going from forward to reverse and vice versa
Coverage and how to read this overview
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
19 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.
0 acknowledgements have no verified action link; they do not establish a repair result.
Generation: 20261027T044418Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
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.
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
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.
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
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.
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.
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.
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.
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
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.
Got some second opinions and they say its the axle shaft that needs to be replaced. I certainly hope so.
There's a place here in town that rebuilds them but their book shows rebuild kits for:
-911
-Carrera
-911 turbo
Would anyone know which kit they should be looking at?
On pelican, the same part # is listed for Carrera 4S and the regular 4. I am thinking, the kit he needs is the "Carrera" one.
Just to be clear, you need the axle shaft that connects the front drive components to the nose of the transmission?
You can have mine. It's been hanging from a rafter in my garage for 4 years. Although it may be suffering from "unsupported camshaft sag syndrome" from hanging in the same position.
