Oil on clutch

[JCKST1]

Hi guys,


I have a 2016 A6 Avant, last month the slave cylinder went on the clutch resulting in my paying quite a lot to have it replaced (gearbox out job plus special order part from Germany!).

We planned to do the clutch and flywheel at the sametime but the mechanic checked the clutch and said it looked ok, we took his word for it however after using the car for a few miles we noticed it is slipping so presume it is properly contaminated. The garage are being helpful and working with us but either way the bill is still a lot, for some reason my clutch and flywheel seems to be more than any others on the range and harder to get (typical).

99% of the time the clutch is fine, we have done about 500 miles in it since and unless you drop a gear or two and have your foot flat on the ground the clutch works like normal.

What do people think we should do, is it worth changing them immediately or should we try and get a few more miles out the clutch and change later in the year, if we do this could it cause any further damage?

If it wasn't for the slave cylinder there would have been no need to even considering changing the clutch.

[Evercross]

Hindsight is 20-20 vision and all that, but you should have overruled the advice and changed the clutch-plate at the very least. If anyone is going to the trouble to split the engine and gearbox it is a no-brainer to change what is a consumable part regardless of its alleged age/condition, for the sake of saving money for the part compared to the labour cost of doing it again later.

What you do from here is your call. You might get lucky and it could just be the surface that is contaminated and clutch grip could improve when it wears a little, or it could go the other way.....

[JCKST1]

We were planning on changing the full lot however when the mechanic had it in bits he said the clutch and flywheel looked fine, plus the parts were not readily available and needed to be ordered in from Germany so it was going to be about 3-4 weeks until they were in and delivered, we were stuck between a rock and a hard place. In the end we got the car back on the road and its been okay but will need doing, I am just unsure whether to try and get the parts now and change it or get as much use out of it as I can.

[Bobupndown]

Drive it for a few weeks to see if it gets worse, or better?

[stevieturbo]

How did oil get onto the clutch in the first place ?

And was it proper good quality, and the correct parts fitted ?

[E-bmw]

stevieturbo said:

How did oil get onto the clutch in the first place ?

And was it proper good quality, and the correct parts fitted ?

Guessing from the failed slave he had changed.

OP?

[JCKST1]

E-bmw said:

Guessing from the failed slave he had changed.

OP?

Correct.

The clutch does seem to be getting better (I think), when we first got the car back and you were putting your foot flat down there was a bit surge through the rev range until the clutch gripped and brought the revs back down now most of the time we can do this without any problem so it seems to be improving but its not perfect. Last week we needed to floor it to get in to a lane when overtaking on the motorway and due to us doing this in 4 & 5th gear the clutch warning light came on the dash but that was excessive, for everyday use so far its no different. I am just worried about any additional damage it may cause or to use it for as long as possible and then change when definitely on its way out.

[stevieturbo]

E-bmw said:

Guessing from the failed slave he had changed.

OP?

That would be brake fluid then ? The two are not the same.

Brake fluid on the friction material tends to make it more grabby, juddery etc as opposed to slipping.

[E-bmw]

stevieturbo said:

E-bmw said:

Guessing from the failed slave he had changed.

OP?

That would be brake fluid then ? The two are not the same.

Brake fluid on the friction material tends to make it more grabby, juddery etc as opposed to slipping.

I am not being argumentative, just asking in my ignorance.

If that is the case when brake fluid gets onto brake shoes, why do the brakes get less effective?

Similar friction materials, same fluid.

[JCKST1]

stevieturbo said:

That would be brake fluid then ? The two are not the same.

Brake fluid on the friction material tends to make it more grabby, juddery etc as opposed to slipping.

There is the occasional judder, mainly when under load and in 1st gear but not all the time.

The main problem is 3-5th gear, when your foot is planted its as if you hit a batch of ice, the car doesn't initially go, the revs shoot up from say 2k - 4k for a second, then it seems to 'grip', the revs go back to normal and the turbo kicks in and your off, if you put your foot down mildly then its fine but I presume the big increases in torque when planted is causing it to do this.

The clutch was 100% fine before the whole slave cylinder saga!

[stevieturbo]

E-bmw said:

I am not being argumentative, just asking in my ignorance.

If that is the case when brake fluid gets onto brake shoes, why do the brakes get less effective?

Similar friction materials, same fluid.

And in the brake shoe scenario, also a loss of hydraulic pressure to the brakes from the leak, and generally it will leak directly onto the friction material.

I would struggle to see how huge amounts of fluid would get onto the disc of the clutch even with a mangled slave in the same manner without other more serious problems first.

I'm not saying brake fluid cannot cause a slip, but brake fluid and oil are absolutely not the same thing, not same properties etc.

And a good dose of brake cleaner will usually get rid of brake fluid even on friction material....not so much with oil.

If the clutch was actually working...I'd certainly be trying to get some access to the clutch, and dosing the F out of it with brake cleaner as a first measure before stripping the entire thing. If you believe the disc is saturated with fluid ( but all slave/hydraulic issues are in good order )

[JCKST1]

stevieturbo said:

And in the brake shoe scenario, also a loss of hydraulic pressure to the brakes from the leak, and generally it will leak directly onto the friction material.

I would struggle to see how huge amounts of fluid would get onto the disc of the clutch even with a mangled slave in the same manner without other more serious problems first.

I'm not saying brake fluid cannot cause a slip, but brake fluid and oil are absolutely not the same thing, not same properties etc.

And a good dose of brake cleaner will usually get rid of brake fluid even on friction material....not so much with oil.

If the clutch was actually working...I'd certainly be trying to get some access to the clutch, and dosing the F out of it with brake cleaner as a first measure before stripping the entire thing. If you believe the disc is saturated with fluid ( but all slave/hydraulic issues are in good order )

I am just going of what I am being told, the mechanic did clean the clutch and also used a blow torch to try and help initially.
As soon as I took it out of the garage and felt the slipping we returned, the mechanic then had the gearbox out two more times fiddling with the clutch, cleaning etc which did help a bit but its still not perfect. As mentioned it does seem to be getting slightly better so I might give it a month and see how I get on, I am planning on a new clutch & flywheel anyway but if I can get a few more months out of it then it will help.

[stevieturbo]

If they actually took the box off again after slipping and did not replace the disc knowing it was covered in some sort of fluid, that seems a bit crazy given the price of a new disc, vs the amount of work it is to remove/refit the box.

A friend did have issue years ago on his BMW when he left it in to a pretend reputable tuning garage to have a new clutch that they recommended. A genuine BMW one.
And it then slipped repeatedly. Seems it has some sort of adjusting mechanism on the cover that needs some sort of setting or release upon install, that they never did and seemingly could not figure out either. 3 or 4 times they had it apart before they figured it out. Which seems mental....but incompetence is everywhere.

I've never worked on one of them myself so not sure what the install of that type of cover actually requires or whether that might be part of the issue with the Audi.

[JCKST1]

stevieturbo said:

If they actually took the box off again after slipping and did not replace the disc knowing it was covered in some sort of fluid, that seems a bit crazy given the price of a new disc, vs the amount of work it is to remove/refit the box.

A friend did have issue years ago on his BMW when he left it in to a pretend reputable tuning garage to have a new clutch that they recommended. A genuine BMW one.
And it then slipped repeatedly. Seems it has some sort of adjusting mechanism on the cover that needs some sort of setting or release upon install, that they never did and seemingly could not figure out either. 3 or 4 times they had it apart before they figured it out. Which seems mental....but incompetence is everywhere.

I've never worked on one of them myself so not sure what the install of that type of cover actually requires or whether that might be part of the issue with the Audi.

To be honest this is why they had it off a couple of times after, the first time he tried cleaning it again and sent me away to try it, before I was even home he called me back as he had spoken to a friend who worked for Audi in the UK (I live in Spain, it was an Englis mechanic) and he mentioned something about a coil/or similar type spring which could be wound back and adjusted, the first time he didn't realise and put it back together, the last time he managed to adjust it and it seemed to work much better, basically put the car in a driveable state except for the above mentioned issue, before he had adjusted it the slipping was much worse and lots of judder so perhaps this needs looking at closer and the clutch/flywheel maybe ok?

Apologies for the basic explanation, as you can tell I am no mechanic.

[stevieturbo]

Perhaps.

As said though, I've never worked on one with the self adjusting mech myself, so not sure. I just know my friend had a nightmare with his and the garage he took it too.
I think it needed some special tool to reset it before assembly.