Transmission thud

[JannerAudi]

For the past six months I have been getting a bit of clutch judder so back in April I took the car into my Audi dealer where they rotated the flywheel through 180 degrees which apparently is an approved Audi procedure to overcome clutch judder. I then tried it over a few weeks to see if it improved as I thought with rotating the flywheel it might need to bed in a bit but clearly it did not work as the clutch judder was still evident some six weeks later.

This past week the car has been back in to my dealer and gladly they decided to replace the clutch, dual mass flywheel and thrust bearing under warranty. I have only had the car back for a couple of days and so not driven very far and although the clutch now feels a bit heavier so far I have not noticed any clutch judder. However, there are a couple of issues that are concerning me a bit and wondered if anyone else has noticed something similar on their manual transmission A6.

Issue 1.
With the engine running and the car in neutral, if I push the clutch in all the way and then let it out a little bit the engine revs rise by say a couple hundred RPM. With some other cars I have had the engine revs change a bit as I let the clutch out but normally the revs drop as a result of load from the gearbox. Also, with the car on level ground, if I creep forward in first gear, then depress the clutch pedal and let it out a bit to maintain momentum there is a slight thud like taking up backlash in the transmission. I had noticed it very slightly before having the clutch changed when parking the car in our garage depressing the clutch and re-engaging it to creep forward but since the clutch change it seems a bit more noticeable. Is it a case that the engine revs rise slightly by design so as to alleviate the likelihood of stalling the engine or is there something strange going on ? Is the thud I get common to all A6 cars or is there a transmission issue ?

Issue 2
I notice that if I sit in the car with the engine running and just tickle the throttle from tick over speed to 1200 RPM the engine rocks the car quite noticeably. Just wondered if this the same with other A6's or is this a weak engine mount perhaps.

Any information from anyone with similar issues (or not) would be appreciated.

Thanks, Janner

[Alan02]

The small rise in RPM when clutch released is normal. The thud, I would get dealer to have a look if you think its more noticeable after clutch fitted. And if you have an erratic idle at increased rpm, again , I would get dealer to investigate as they possibly could be related to having the work done.

[mshaw1280]

I had my clutch and dual mass fly wheel replaced and I still get judder when pulling away but not as bad as it was. I get an odd vibration when pulling through 2200 rpm to about 3000 too - sounds like the windshield is going to vibrate off the car!! I'm thinking that there's an issue with the fit of the engine mounts too but no issues found by main dealer. Not impressed with the car, in fact one of the biggest let downs.

As far as your issue 2 goes I too noted that my car is rocked by the rpm increase in neutral but didn't think much of it til now.

Off to an independent next week so I will post if anything found.

[rose5691]

I have a similar problem on my A3 TDI- when you switch the engine off there is a horrible clunking sound coming from the flywheel area....

[JannerAudi]

Update,
Took my car to my Audi dealer and their master technician could feel the thud when letting the clutch out but was unsure what is causing it. They didn't have another manual A6 there at the time to make a comparison but the tech said another manual A6 was due in the next day and he would check it out and let me know how it compared. Didn't hear anything for a week so contacted them and they said this other A6 was the same.

Later today I am calling in to try this other A6 myself but in my opinion there should not be any thud present at all with any A6 or any manual transmission car. It feels like backlash in the transmission chain somehwere. To me it suggests a problem with either the clutch release bearing, DMF, gearbox, driveshaft or CV joint.

I would like to know if anyone else out there with a manual A6 is getting any thud or knock when they intially let the clutch out or is your clutch silky smooth. I can overcome it by being very very gentle letting the clutch out but if I pull away a bit smartish at a junction or roundabout there is definitely a thud. It also happens in slow moving traffic dipping the clutch and the re-engaging it.

[A6S]

I would get them to check the engine/gearbox mounts as these are rubber and might not have seated right when they refitted everything. That could be the cause of the thud and vibrations.
Revs rising or dropping in neutral is normal as even though the car is in neutral there is still fluids that's there. You will probably find it more noticeable when the cars cold than warm.