15 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHC4S/C4 Differential Issues?
Leading reported evidence
Replace also
Performed · outcome unconfirmed
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 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
Surfing the 996TT forum shows some members with their front diff replaced also -- but that's a different issue (I believe) because the 996TT has much more torque and hp than the NA counterpart.
Leading evidence: 'Replace also' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Replace also' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. 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
Hey guys, I just had my C4S's front diff replaced under extended warranty.
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
I've thought about getting a C4S Cab to replace the C2 Cab I recently sold.
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
Dell, I've been running the 18" OEM Turbo Twists for a majority of the 32k miles, up until about 31k miles when I put the 19" wheels, with similar rolling diameters.
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
I had this in mind, but there are a lot of 996TT people running 19's and spme don't seem to have issues, but I found that some have had issues.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Replace also
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
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
Surfing the 996TT forum shows some members with their front diff replaced also -- but that's a different issue (I believe) because the 996TT has much more torque and hp than the NA counterpart.
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
Dell, I've been running the 18" OEM Turbo Twists for a majority of the 32k miles, up until about 31k miles when I put the 19" wheels, with similar rolling diameters.
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.
15 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: 20261027T173940Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
Hey guys, I just had my C4S's front diff replaced under extended warranty.
After doing a search, it seems other cars (C4/C4S) have had issues with their diffs also, even "stock" ones.
Does anyone out there know if this is a weak link for the AWD 911's?
I don't want to have to worry about this every 30k miles. My car only has 32k miles and it had issues. Total bill was around $3200, my deductible was only $50. However, my ext. warranty ends in 6 months.
I'd like to know if this is a "recurring theme," if some of you out there have seen/read anything about this. I can't find any other info about it.
Thanks.
No postmortem from the dealer. They had it for a week and I just got it back today.
I just heard some grinding noise when cruising downhill with the tranny in neutral. At first I thought it was a bad wheel bearing, which would be tolerable.
Surfing the 996TT forum shows some members with their front diff replaced also -- but that's a different issue (I believe) because the 996TT has much more torque and hp than the NA counterpart.
I've thought about getting a C4S Cab to replace the C2 Cab I recently sold. I also wondered about disconnecting the front diff, and driveline and possibly front axle shafts like guys are doing on the TTs. Ever heard of this? It would be like the C2S of the late '90s, TT body, suspension, brakes and rear wheel drive, like a n/a GT2.
This would eliminate your front diff issues and give you the fun factor (motorcycle handling) of tail heavy RWD.
My indy said it was pretty much bulletproof... and he works on very high HP turbos. I'd be very interested in learning what exactly went wrong.
But hey, nice save by your ext warranty!
Nick, I tried the RWD solution by removing the driveshaft (~45 min job) for about a week. It isn't as fun as people make it out to be. It's RWD with an open diff, so PSM still "acts up" even if you turn it off. Removing the driveshaft and putting an LSD in the rear would be perfect.
Dell, I've been running the 18" OEM Turbo Twists for a majority of the 32k miles, up until about 31k miles when I put the 19" wheels, with similar rolling diameters. I had this in mind, but there are a lot of 996TT people running 19's and spme don't seem to have issues, but I found that some have had issues.
I'll contact the SA on Monday and see if they've documented something or if they plan to do a postmortem. My ext. warranty pretty much authorized it without question. They did have to come out and verify that it had a grinding noise; but aside from that, they didn't deny coverage due to the 19" wheels.
The more I think about it, I highly doubt it's due to the wheels/tires. I've only had this set for 1k. The rest of the time, I've been using the stock 18" twists for canyon runs and track days.
Maybe it was a fluke, a typical 6-sigma case.
Really? I didn't think Conti made a 315 in the CS2. In the new CS3 tire they do.
Regardless, if those are the sizes you are running then they are almost identical in diameter and revs. Can't imagine that would be the contributor to the diff issue.
