Is My Shaft Normal?!?!

[S3Alex]

Hi and sorry about the dodgy title but I though it would get extra attention and I need help urgently. Also I mean the title literally.

I'm having clutch/flywheel problems with my 2007 8P S3 and my mechanic can't find anything wrong. I just had a new clutch, dual mass flywheel and release bearing installed and now I have these problems...

1. Droning noise when I decelerate through 2500rpm.
2. Occasional rattling noise from the gearbox when I let the clutch out.
3. Occasional knocking noise at idle and in neutral.
4. Clutch pedal shakes/judders and gear lever too.
5. Occasional power loss/surge.
6. Stiff gear changes in all gears and sometimes won't go in at all.

Anyway, back to my shaft...

I got my mechanic to take the gearbox out again because I said I wasn't happy. I was hoping to see something obviously wrong but there wasn't, except maybe... my input/clutch shaft splines.

Do the splines on the end of the input shaft have little ridges? It's like they are serrated all along the tops of the splines. Also I thought I could feel a slight mushrooming on the splines. The last 10mm of the shaft felt wider than the rest of the shaft. The other thing I noticed is that it had no grease on it, bone dry. Also there were streaks of grease coming out of the middle of the clutch hub/centre. Sorry I don't know the right words for the parts but I hope I'm making sense.

Is it possible there was no grease or too little grease or the wrong grease on the shaft?

Any help here would be greatly appreciated.

Hi,

Joking aside,the first thing I'd say is that if all this has started since replacing the clutch and DMF,then that's the cause of the problem,and it's the mechanic's job to sort that out.

All of the problems there would fit with the clutch plate not moving correctly on the splines,and if,as you say,the splines are ridged and mushroomed,then they sound either worn or damaged.

If you google gearbox shaft splines,you'll get a very good impression of what they should look like.....elongated teeth as on a gear but longer,and smooth down their sides and top.
They should not be ridged,scarred or obviously worn.
If the shaft is completely free of grease,that may also lead to the clutch plate sticking.

I can understand a little bit of grease from the centre of the clutch bearing,as long as this hasn't got onto the clutch plate itself,as this would also knacker it,but it would slip rather than judder.

Was this done at an Audi dealership?....if so,drive it up there,park it and complain loudly in the showroom until it gets sorted....failing that,a phone call to VAG customer services may also concentrate a few minds.

I appreciate that the most likely cry will be one of wear and tear,but a splined shaft is not expensive,and is pretty easy for them to replace,but the point is they should have noticed,and informed you,rather than giving you back a car that doesn't quite work.

This picture isn't great,but it does show the shaft I think you're talking about,running into the box,and it isn't ridged or damaged.

 

[chadvaliant]

I went to have a closer look at my gearbox but the ridges on the splines seem to be machining marks and I think it's ok. So I really don't know what's wrong with my car.

I spoke to LUK UK and they said that some VAG cars have had an issue where the main gearbox input shaft becomes loose and causes most of my problems. He couldn't tell me what the definition of loose was though. Apparently the shaft gets some play in it and can be pushed and pulled in and out. Does anyone know how much play is allowed? Mine's got about 1mm.

There is something else that might be worth mentioning here. If I reverse somewhere and then go forward I get a strange noise. It's a small grinding noise that lasts less than a second. The mechanic said it was the brake pads shifting. I never really worried about it but it might be relevant. The other possibly strange thing is that I find reversing difficult, almost like reverse has a similar ratio to 3rd. It's very easy to stall in reverse.

Any ideas?

 

[S3Alex]

I went to have a closer look at my gearbox but the ridges on the splines seem to be machining marks and I think it's ok. So I really don't know what's wrong with my car.

I spoke to LUK UK and they said that some VAG cars have had an issue where the main gearbox input shaft becomes loose and causes most of my problems. He couldn't tell me what the definition of loose was though. Apparently the shaft gets some play in it and can be pushed and pulled in and out. Does anyone know how much play is allowed? Mine's got about 1mm.

There is something else that might be worth mentioning here. If I reverse somewhere and then go forward I get a strange noise. It's a small grinding noise that lasts less than a second. The mechanic said it was the brake pads shifting. I never really worried about it but it might be relevant. The other possibly strange thing is that I find reversing difficult, almost like reverse has a similar ratio to 3rd. It's very easy to stall in reverse.

Any ideas?

Let's get the brake noise out of the way first......pads can slide back and forwards a little,and it may make a clunk or similar noise when you shift from forwards to reverse.

I can't see 1mm play causing all of the issues you're experiencing,especially when all of this started AFTER the new clutch was fitted.

Either something has not been installed/adjusted correctly,or there is another issue here,but as I said,if this is an Audi dealership,and they fitted this using Audi approved parts,and it was working properly prior to fitting,the problem is theirs.

Did any of them actually drive it and try to tell you it was OK?

 

[chadvaliant]

Hi,

Joking aside,the first thing I'd say is that if all this has started since replacing the clutch and DMF,then that's the cause of the problem,and it's the mechanic's job to sort that out.

All of the problems there would fit with the clutch plate not moving correctly on the splines,and if,as you say,the splines are ridged and mushroomed,then they sound either worn or damaged.

If you google gearbox shaft splines,you'll get a very good impression of what they should look like.....elongated teeth as on a gear but longer,and smooth down their sides and top.
They should not be ridged,scarred or obviously worn.
If the shaft is completely free of grease,that may also lead to the clutch plate sticking.

I can understand a little bit of grease from the centre of the clutch bearing,as long as this hasn't got onto the clutch plate itself,as this would also knacker it,but it would slip rather than judder.

Was this done at an Audi dealership?....if so,drive it up there,park it and complain loudly in the showroom until it gets sorted....failing that,a phone call to VAG customer services may also concentrate a few minds.

I appreciate that the most likely cry will be one of wear and tear,but a splined shaft is not expensive,and is pretty easy for them to replace,but the point is they should have noticed,and informed you,rather than giving you back a car that doesn't quite work.

This picture isn't great,but it does show the shaft I think you're talking about,running into the box,and it isn't ridged or damaged.

Thanks Alex.

No it wasn't an Audi dealer. I couldn't go back to my local dealer after they messed up my diff.

Here's a pic of those ridges, they're small but I assumed if there was something meant to be sliding on it then it should be smooth.

Ok I can't seem to add a pic. Can you imagine the tops of the splines having lots of ridges like a file. The ridges are at right angles to the splines and shaft. They seem too uniform to be anything but manufacturing machining though.

 

[chadvaliant]

Let's get the brake noise out of the way first......pads can slide back and forwards a little,and it may make a clunk or similar noise when you shift from forwards to reverse.

I can't see 1mm play causing all of the issues you're experiencing,especially when all of this started AFTER the new clutch was fitted.

Either something has not been installed/adjusted correctly,or there is another issue here,but as I said,if this is an Audi dealership,and they fitted this using Audi approved parts,and it was working properly prior to fitting,the problem is theirs.

Did any of them actually drive it and try to tell you it was OK?

The reverse to forward noise is more of a deep grind or graunching noise but like I say it lasts for a very short time and never happens again until I use reverse again. It doesn't sound like brake pads to me.

I've taken the car back to the mechanic a number of times and they have tried a number of different things to fix the problems. They thought the droning noise was the exhaust. They thought the power loss/surge was the computer re-learning. They thought the gear changes would be fixed with new oil. They think the gear changes are acceptable and they have only experienced mild pedal pulsing and they said it's ok.

 

[S3Alex]

The reverse to forward noise is more of a deep grind or graunching noise but like I say it lasts for a very short time and never happens again until I use reverse again. It doesn't sound like brake pads to me.

I've taken the car back to the mechanic a number of times and they have tried a number of different things to fix the problems. They thought the droning noise was the exhaust. They thought the power loss/surge was the computer re-learning. They thought the gear changes would be fixed with new oil. They think the gear changes are acceptable and they have only experienced mild pedal pulsing and they said it's ok.

OK....I see what you're getting at,and it doesn't sound brake related at all.

The ridges across the top of the splines at right angles will be machining marks.

It sounds to me as if they're trying to find a way out of this......if the car was changing gear without problems prior to the clutch being changed,why should changing the gear oil make any difference at all.

Given the number of excuses/explanations you've had(brake pads,exhaust,ECU learning,gearbox oil) it really does come across as them not having any idea what the cause of the problem is.

Without naming names(or maybe we should),is it a well known independent,and an Audi specialist,or not?

 

[chadvaliant]

OK....I see what you're getting at,and it doesn't sound brake related at all.

The ridges across the top of the splines at right angles will be machining marks.

It sounds to me as if they're trying to find a way out of this......if the car was changing gear without problems prior to the clutch being changed,why should changing the gear oil make any difference at all.

Given the number of excuses/explanations you've had(brake pads,exhaust,ECU learning,gearbox oil) it really does come across as them not having any idea what the cause of the problem is.

Without naming names(or maybe we should),is it a well known independent,and an Audi specialist,or not?

I'm not from the UK so even if I named them it wouldn't help anyone else. They claim to be a euro car specialist and they were highly recommended. I don't really want to name them at this stage for another two reasons, one, I don't know yet if they are at fault and two, they might be reading this as they try to fix my car. The problem I have is that S3s are rare in my corner of the world. Like I said in an earlier post, I went to a different euro specialist for advice and they didn't know what LUK or a dual mass was. Strange considering his workshop was full of late model BMWs.

I guess my question now is... Do I tell the mechanic to crack the gearbox open or do I tell him to put the car back together and just hope that it works?

What is reverse like for you guys? Do you feel like it's highly geared? Do you stall sometimes in reverse?

 

[TDI140]

Thats a question for the doctor

 

[S3Alex]

Reverse is normally a pretty short gear but should engage easily.

I hadn't realised you were outside the UK but the same rules should apply with a decent dealer.

Good luck.

 

[chadvaliant]

I finally managed to upload a photo. I have a feeling it's an Internet Explorer bug.

Anyway... Those are the ridges I was talking about, if you can see them. Also I notice my release bearing is rusty but Alex's was mint. This is a brand new bearing apparently.

 

[phil76]

1. Droning noise when I decelerate through 2500rpm.
2. Occasional rattling noise from the gearbox when I let the clutch out.
3. Occasional knocking noise at idle and in neutral.
4. Clutch pedal shakes/judders and gear lever too.
5. Occasional power loss/surge.
6. Stiff gear changes in all gears and sometimes won't go in at all.

I wouldnt be looking into anything myself if you have paid for the work doing and it wasnt like it before its something thats not correct simple as,having to force a car in to gears is just going to damage the box if isnt already damaged,seek citizens advice,take your car back and say you want it sorted or tell them you will take it somewhere that can sort it and you will send them the bill.

isnt there a decent independant specialist near you who you could ask there advice ?
i wouldnt know if the power loss and surging would be related though ,as mentioned the droaning is normally gearbox or prop bush issues but all other problems are or sound like clutch or gearbox related.

 

[S3Alex]

View attachment 17301
I finally managed to upload a photo. I have a feeling it's an Internet Explorer bug.

Anyway... Those are the ridges I was talking about, if you can see them. Also I notice my release bearing is rusty but Alex's was mint. This is a brand new bearing apparently.

Given the machine markings on the shaft,I'd say it probably is pretty new,but there is no sign of any grease on the shaft at all,so that may be the problem.
The clutch bearing and splines must have something to lubricate them or they'll grate constantly.

 

[chadvaliant]

I wouldnt be looking into anything myself if you have paid for the work doing and it wasnt like it before its something thats not correct simple as,having to force a car in to gears is just going to damage the box if isnt already damaged,seek citizens advice,take your car back and say you want it sorted or tell them you will take it somewhere that can sort it and you will send them the bill.

isnt there a decent independant specialist near you who you could ask there advice ?
i wouldnt know if the power loss and surging would be related though ,as mentioned the droaning is normally gearbox or prop bush issues but all other problems are or sound like clutch or gearbox related.

Thanks Phil. What I'm really worried about is if I tell them to fix the flywheel but it turns out to be something else then I'm out of pocket nearly two grand. That same theory applies to any individual part. If I tell them to just fix "it" then they say it was fine the way it was. That's why I'm trying so hard to find the smoking gun.

In regards to a decent specialist, I've spoken to quite a few but they all say that it could be clutch, flywheel, release or gearbox. They have no idea. Also if I got someone else to do the work I would have to pay up front and hope that the current mechanic will pay me back. That's a risk I can't afford to take.

 

[chadvaliant]

Given the machine markings on the shaft,I'd say it probably is pretty new,but there is no sign of any grease on the shaft at all,so that may be the problem.
The clutch bearing and splines must have something to lubricate them or they'll grate constantly.

I thought the splines looked really dry too. I thought that would explain the intermittent pulsing and gear changes. I wondered if they used a low melt grease and it flew off early onto the clutch to give me the surges.

 

[S3Alex]

I thought the splines looked really dry too. I thought that would explain the intermittent pulsing and gear changes. I wondered if they used a low melt grease and it flew off early onto the clutch to give me the surges.

Or just not put anything on it at all...what you saw on the clutch could easily be the remnants of whatever he used.

 

[phil76]

OK....I see what you're getting at,and it doesn't sound brake related at all.

The ridges across the top of the splines at right angles will be machining marks.

It sounds to me as if they're trying to find a way out of this......if the car was changing gear without problems prior to the clutch being changed,why should changing the gear oil make any difference at all.

Given the number of excuses/explanations you've had(brake pads,exhaust,ECU learning,gearbox oil) it really does come across as them not having any idea what the cause of the problem is.

Without naming names(or maybe we should),is it a well known independent,and an Audi specialist,or not?

I have had it on mk4 golf 6 speed golfs where an after market equivlant of the dealer gearbox oil was put in the gearbox and the car wouldnt hardly go in gear until it started warming up,i had this with mine thats why i know not to put anything other than the dealer oil in them,( i am not saying thats your problem)
i dont know what to tell you mate if your scared of more damage,they wont do anything,and you dont want to pay anyone else to look at it ,thats a bad situation

 

[bmh.01]

Is the droning noise coming from the rear and is it more noticable in the higher gears? If so its the rather common rear propshaft donut.

The release bearings also tend to rattle a bit as they aren't kept tight to the clutch pressure plate fingers, if you slighty depress the clutch pedal (without operating the clutch 5-10mm max) does the rattle stop?

Also that's a perfectly normal input shaft.

2,4,5 can you elaborate more on those?

6 is poor gear linkage alignment, does he know how to get the linkage with the locking pin on the gearbox and a rod/drill bit to lock the gear stick?

 

[chadvaliant]

Is the droning noise coming from the rear and is it more noticable in the higher gears? If so its the rather common rear propshaft donut.

The release bearings also tend to rattle a bit as they aren't kept tight to the clutch pressure plate fingers, if you slighty depress the clutch pedal (without operating the clutch 5-10mm max) does the rattle stop?

Also that's a perfectly normal input shaft.

2,4,5 can you elaborate more on those?

6 is poor gear linkage alignment, does he know how to get the linkage with the locking pin on the gearbox and a rod/drill bit to lock the gear stick?

Hi BMH, thanks for your answer.

1. Droning noise when I decelerate through 2500rpm. The noise is deep and hard to pin point but definitely not from the rear. It sounds like a big bore exhaust but from the engine bay. Sometimes it's bad and sometimes it's not there at all.

2. Occasional rattling noise from the gearbox when I let the clutch out. This happened to me once where I was in a car park and I selected reverse to get out and as I started lifting my clutch it started rattling like a couple of coins in a tin can. I put my foot back on the clutch and it went away. The next time I tried it was fine. It wasn't a grinding noise like a poorly selected gear but a clean dry rattle. Unless these cars grind like that and I'm just not used to it. I'm sure I would have felt more through the lever if it was a gear grind.

3. Occasional knocking noise at idle and in neutral. This scares me a lot too. It was just sitting there idling one morning going clunk, clunk, clunk. There was no set pattern but there was a lot of it. One or two clunks a second.

4. Clutch pedal shakes/judders and gear lever too. This has happened a few times and I find it the most alarming problem. Sometimes when I put my foot lightly on the clutch pedal there is a vibration and sometimes that vibration is a full on shake. The shake can be felt through the gear lever and the clutch pedal only. It's a severe pulsating though.

5. Occasional power loss/surge. This happened quite often to begin with but less frequently now. I would basically slowly press the accelerator and there would be only slight acceleration and then suddenly it would jolt forward. This is not from a stand still, this is when doing about 40 or 50kmh. I never got to see if the revs were doing anything strange as it all happened quite quickly. So I don't know if it was clutch slip.

6. Stiff gear changes in all gears and sometimes won't go in at all. I don't know what he did when he put it back together, sorry. I could ask him but would that be an offensive question to a mechanic or is this a trick with these cars.


When you say that the shaft is normal, do you think that the amount of grease is normal too?


Do you know how much play the input shaft should have? How far should I be able to pull it out of the gearbox? I've googled that question until my fingers bled but no answer as yet.

 

[chadvaliant]

I have had it on mk4 golf 6 speed golfs where an after market equivlant of the dealer gearbox oil was put in the gearbox and the car wouldnt hardly go in gear until it started warming up,i had this with mine thats why i know not to put anything other than the dealer oil in them,( i am not saying thats your problem)
i dont know what to tell you mate if your scared of more damage,they wont do anything,and you dont want to pay anyone else to look at it ,thats a bad situation

When I did my 60000km service I insisted on genuine oil and when these guys drained it 9000km later I was furious but they told me they replaced it with genuine oil.

Another strange thing is that it seems like the gear changes are less notchy when it's cold.

It's not so much a matter of me not wanting to pay someone else to do the job and then try to get my money back. It's a matter of me not being able to afford to do that. If I had a spare three grand then I would have risked it. I just recently got made redundant and so things are tight.

 

[bmh.01]

When you say that the shaft is normal, do you think that the amount of grease is normal too?


Do you know how much play the input shaft should have? How far should I be able to pull it out of the gearbox? I've googled that question until my fingers bled but no answer as yet.

Shaft looks normal, ideally there shouldn't be any play at all in the shaft, but there will probably be a bit (less than 1mm at the most) in and out, there should be none up/down side/side. Anything excessive indicates worn input shaft bearings.

Grease is normal but you certainly have other issues, 2,4 and 5 are very wrong and the others aren't ideal either. If drone is from the front its possible the mechanic has damaged the front prop joint, or it's now bolted up in a different orientation than before and now showing the wear.

Rattle on idle can be normal but you should have to listen for it, it shouldn't be obvious. Bearing in mind that you now are listening for it automatically now you're aware of it.

 

[chadvaliant]

Shaft looks normal, ideally there shouldn't be any play at all in the shaft, but there will probably be a bit (less than 1mm at the most) in and out, there should be none up/down side/side. Anything excessive indicates worn input shaft bearings.

Grease is normal but you certainly have other issues, 2,4 and 5 are very wrong and the others aren't ideal either. If drone is from the front its possible the mechanic has damaged the front prop joint, or it's now bolted up in a different orientation than before and now showing the wear.

Rattle on idle can be normal but you should have to listen for it, it shouldn't be obvious. Bearing in mind that you now are listening for it automatically now you're aware of it.

The rattle in reverse was very noticeable. It was like a someone sitting in the engine bay shaking a can of coins as hard as he could.

The clunk/knock at idle was less noticeable but still very worrying. I have a video of the clunk noise, I'll try to upload it.

Hmmm... Seems I need to put it on YouTube or Dropbox or something. Does anyone want to hear it?

 

[chadvaliant]

Do you know how much play the input shaft should have? How far should I be able to pull it out of the gearbox? I've googled that question until my fingers bled but no answer as yet.

I spoke to someone who claimed to be the head mechanic at the largest Audi dealer in my corner of the world and he said between 0.1 and 0.5mm is acceptable. I put this here in case someone else needs that info.

 

[chadvaliant]

I have uploaded these to YouTube....

This one is the clunking/knocking noise. You might need headphones to hear the clunking over the normal clicking and ticking.

IMG 0542 - YouTube


This one is of the various parts sitting on the mechanics bench. Sorry about filming it in the wrong orientation. The filming is also average at best as I couldn't see the screen very well.

IMG 0555 - YouTube

 

[chadvaliant]

Does anybody have any insight on the YouTube clips? Apart from the fact that I shouldn't be looking for a job as a camera man.