A6 Multitronic CVT judder (Full Version)

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A6 Multitronic CVT judder

  

dane -> A6 Multitronic CVT judder (12/23/2004 10:33:46 AM)

I have a 2000MY A6 fitted with the 2.4 litre gasoline engine and the Multitronic CVT tansmission. The transmission has approximately 25,000 miles on it from brand new. Recently the vehicle has started to judder when coming to a complete stop. Almost as if the clutch is not disengaging correctly. The local Audi dealer simply told me the clutch was slippping and I would need a new gearbox (£4,500!!). However when pulling away from a standstill the vehicle behaves normally. Privately I have been advised to change the transmission fluid which I'm about to do. Audi state that the CVT fluid is 'fill for life' but other posts indicate this is not the case (especially for the other autos). Does anyone have any experience of a Multitronic CVT behaving like this?
David.

  
shabaz -> RE: A6 Multitronic CVT judder (12/27/2004 6:38:04 PM)

In the UK the CVT transmission oil needs replacing every 40,000 miles and requires the gearbox temperature to be at 45C. Use VAGCOM software to do this. Also you will need a special refill tool VAS 5162. The refill method is impoertant and must be done with the engine running to as the temperature rises to 45C, excess fluid runs out. The filler plug must be secure brfore the engine is switched off otherwise a litre of fluid will be lost. I am not aware of any failures in the UK but I would chanage your oil first to see if there is an improvement. Make sure that whoever does it, they know what they are doing.

dane -> RE: A6 Multitronic CVT judder (1/5/2005 5:51:26 AM)

Thanks for the advice. Are you sure the engine should be running when the new transmission fluid is added? The instructions which I have from Audi are unclear about this. Having changed the fluid I still have the same problem but the fluid was changed with the engine off. Should I top it up with the engine running?

shabaz -> RE: A6 Multitronic CVT judder (1/5/2005 10:08:04 AM)

Absolutely sure. With the engine off, pour in about 5.5 litres in and then start the engine. Wait until the oil temperature reaches 40C to 45C. as temperature rises, excess oil will flow out. When 40C is reached then close the filler plug. If you switch the engine off before closing the filler, then you will see 1 litre of oil pour out.

If you let me have your address, I will post to you the Audi instructions from Erwin. The file is secure and does not allow me to e.mail it to you. alternatively you can purchase the maintenance docs from the Erwin web site for about 18Euros.

Regards

shabazmo@aol.com

dane -> RE: A6 Multitronic CVT judder (1/6/2005 11:58:51 AM)

Thanks a lot for the advice. I added a further two litres of ATF (since I know I had 3.6 litres in the transmission already) with the engine running and then rechecked the level when the VAG unit showed the ATF temp had reached 35°C. This left another 700 ml of fluid in the transmission. The car definitely feels slightly different although the judder is still there when I pull to a stop. Could running the gearbox with low fluid level have caused this problem? Could I adjust the multi-plate clutch clamping pressures using my VAG unit?

shabaz -> RE: A6 Multitronic CVT judder (1/6/2005 2:17:39 PM)

I am afraid that I am out of my league on CVT diagnostics. I am still concerned that you may not have the correct amount of fluid in your transmission. Have you used the VAS5162 tool and did you let the excess fluid drain away when the engine warmed up. I will try to find a CVT diagnostic manual that may help you. Also have you used the correct fluid. G052 180 A2 Audi CVT fluid.

Keep in touch and let me know how you get on.

shabaz -> RE: A6 Multitronic CVT judder (1/6/2005 3:52:17 PM)

Check out the audi service web site http://www.erwin.audi.com. They do a CVT self study guide for about 7 dollars. It is about 100 pages and will tell you more about how the transmission works.


dane -> RE: A6 Multitronic CVT judder (1/10/2005 6:40:42 AM)

Again thanks for the tip. I have the CVT self-study guide from the erWin site and it's great. It is also the only place where I have found a guide to oil volumes in the CVT Multitronic transmission. It states that this transmission should have approximately 4.5 litres of fluid from a regular change. Now I have checked my fluid level using the service equipment with the engine running and at 40°C and I have barely got 4 litres in there. This is after I got an extra 700ml with the engine running. The car feels different with this extra oil but the judder remains. I am very tempted to put a further 700 - 800 ml of oil into the transmission. Anyone have an opinion on whether a small additional amount of oil might cause a problem?

dane -> RE: A6 Multitronic CVT judder (2/14/2005 6:25:01 AM)

Here's the end of the story. Unusually for me it's a happy one! Having found an Audi engineer at Ingolstadt who would discuss the Multitronic gearbox it seems that it is almost unheard of for the clutch to fail in normal service. So I stripped the front end looking for other clues and found that both the front wheel speed sensors were not seated quite properly. Refixing these has completely cured the problem. I cannot explain why I did not see a VAG or dash error nor why the engine speed seemed to hang high until the vehicle was completely stopped. Either way I've avoided a £4k transmission exchange!

SilverA6Biturbo -> RE: A6 Multitronic CVT judder (2/19/2005 2:09:50 PM)

Hey is it possible that my Automatic A6 could be suffering from the same?? at decel whel braking its like it jerks and suddenly drops rpm...tried turning off the ESP and havent seen that behaviour

dane -> RE: A6 Multitronic CVT judder (2/22/2005 5:57:14 AM)

Do you feel any pulsing through the brake pedal? My symptoms were pulsing through the brake pedal (just like the ABS firing off) immediately before the vehicle came to a stop with the engine speed staying high and then suddenly dropping to idle just as the vehicle actually stopped. If you are seeing these then I would strongly suggest that you look at the wheel speed sensors. Bear in mind that I saw no warning lights while my car displayed these symptoms and my VAG unit showed no fault codes. I simply removed the wheel speed sensors, cleaned them (and their housings) and refitted them with the correct clearances and I have not seen the problem again.

Garth -> RE: A6 Multitronic CVT judder (3/22/2005 4:02:29 AM)

Dane - any chance of posting the details of the Audi man you spoke to in Germany. I need to speak to someone who really knows about these boxes too. I have had conflicting views about my problem from two different garages.

dane -> RE: A6 Multitronic CVT judder (3/22/2005 8:37:50 AM)

Garth. I have to confess to not speaking to the Audi engineer personally but via a business colleague who works in Germany (as I don't speak German). I will see what I can do but please be aware that I may not get any contact details as I had to call in a favour to get the information in the first place. In the meantime have you looked at the Audi Self-Study Program for the 01J Multitronic gearbox. You can buy it from the erWin website for about €5. It is really helpful in explaining how the box works. I believe that spare parts for the 01J gearbox should now be available through the Audi spares network although I couldn't find anyone who would let me have a parts listing. Until I found my problem was unrelated to my gearbox I was all set to have the box overhauled by JP Automatic Transmissions (www.jpat.co.uk). I spoke to Bruce Palmer at JP who was confident he could do the work if they could get seals and gaskets which as I mentioned already is the problem. Hope this helps. I'll see what I can do about getting a contact at Ingolstadt.

hanif001 -> RE: A6 Multitronic CVT judder (11/11/2006 10:07:38 AM)

I recently bought an A6 2.5 TDi with the multironic gearbox. When I test drove the car it run perfectly. However, after I got it home (all running gear well warmed over a 30 mile journey), I noticed the gear changes were not smooth and jerky. Grrrr - too late now! Ebay purchase, no refunds!

Anyway, I checked google - just to find that its a common problem. The car has done 85k miles and I dont think the transmission fluid has been changed. I bought 6 litres of the transmission from the main dealer (as there doesnt seem to be a 3rd party equivalent). As mentioned above, the box takes 4.5 litres.

Now comes the interesting part. I recently bought some engine addative to free-up stuck hydraulic tappets. This stuff comes in a 200ml bottle and is to be mixed in 5L of engine oil. After reading about expensive CVT clutch replacements I decided to add a bit of the addative to the CVT refill oil. Before using it I mixed the two oils to make sure that there wasnt a bad reaction (eg, oil emulsifying, cloudy etc). Kept it for a few hours and as seemed well.

So I added about 20ml of the addative to the 4.5L of the audi oil. Refilled the gearbox as in the above postings.

With the refill completed, the gearbox felt worst that before. When cold, the car ran ok for a little while, but after about a mile or two, the take-off gear changes were very clunky (large amounts of judder). I though the gearbox was finished and would need the expensive repairs everyone is talking about in these forums. But I had to use the car over a 50 mile journey (round trip). The journey started off badly, with me helping out the gearbox by taking it easy on the acclerator during take off to keep the juddering acceptable. But after about 10 miles, I noticed the gearbox improve. The judders were reducing (even with the gearbox getting to normal working temperature).

Now that the cars covered about 100 miles, the judder has almost disappeared. I am hoping to change the auto fluid again after about 2k miles. Next time I will add about 10ml of the addative. Going to change the gearbox oil again after another 3k miles and then finally, just use the audi fluid only. Subsequently, I am intending to change the gearbox oil every 20K miles as its not a difficult job once you have done it and know the refilling tricks.

The above fix may not work for everyone, but I wanted to share the knowledge as it could save you a load of money. The addative I used is:

"DX Tune Up" - for sticky hydraulic tappets and valves
Unipart Automotives
Unipart House
Cowley
Oxford
OX4 2PG
44 10865 778966

I am not sure whether the oil change would have cleared the judder without the addative. The old oil was quite thick and black (new is a clear amber) so it need the change eitherway. I have no idea why manufacturers give the marketing guys so much power to cliam lifetime operation. The only guarantee we have in life is that we will die one day.

martinstokes -> RE: A6 Multitronic CVT judder (12/2/2006 1:08:18 PM)

very interesting, well to me, anyway. I recently bought an a6 2.4 multitronic which has water in the gearbox because the heat exchanger in the radiator perforated. Anyway I have rather optimistically fitted a new radiator and timing belt etc while the front is off, and have emptied the gearbox hoping it will recover. But something I can't find in all these posts and which is making me feel very dim, is how ON EARTH do you re-fill the gearbox, and where?

martinstokes -> RE: A6 Multitronic CVT judder (12/3/2006 7:09:01 AM)

Oh, I just found out. In case anyone else is as dim as me, here is the information I was looking for. Both filler and drain are under the gearbox about 50mm apart. the drain is the one with the thead showing and the special tool socket which is like a very large security torx (however if one is desperate the plug comes out with a good pair of mole grips - I was not the first, the specialist garage that I took it to earlier used mole grips as well!). The filler is the one next to it, identical to the filler on the side of the diff. To fill, you need the special tool, however I managed fine with a pump and a female 1/2 inch thread reducer onto the pump pipe which will thread very gently into the hole with the help of some ptfe tape. Then fill up as described in other posts. Why they have made it so difficult to refill the gearbox is quite beyond me - this car had a damaged radiator which leaked water into the gearbox, surely something which must happen quite a lot.

pdubelloy -> RE: A6 Multitronic CVT judder (3/27/2007 1:02:55 AM)

I'm in Chile South America, and have a problem in my 2003 1.8 Turbo A4 Multitronic (CVT). The transmission stop to working in a red light, and i have to pull the car to the dealer. They believe to be the gear box ECU, and as far i cand search on internet it's a comon failure in this transmissions (as the clutch). My car has 40.000 kilometers, fully maintained in the oficial dealer, and i have found no response untill now. The car has been there for one month and a half waiting for a factory courtesy... How long so i have to wait?... I don't know, but the new ECU cost EUR 1.650,00 plus hand work at dealer. I think this is a robery.
Last week I wrote to AUDI.de they reply telling me that the Chilean Importer is going to contact me... What for? my car is at their service and they can't do nothing...
I have found a workshop in the US that said they can fix my ECU. They are AUTOECU.com, and the rebuild cost will be about USD349 whith 3 year warranty (2 more than AUDI factory warrany). What if the fali is not the ECU and is the Clutch?
By now I'm still waiting for my dealer (also the official importer) answer about my car.
Fortunatelly I have other cars now, plus many other before and Never an unsolved problem. This is the first time, and in a soupoused to be "super car (Vosprung Durch Teknik)". What is the diference between AUDI and LADA, YUGO, or Chinesse cars??? Aha!!! THE PRICE (Maybe the other are better)
If any one knows how to get some factory answer and repair, please tell me.
To who is thinking to buying an AUDI... Beware!!! and learn from those (us) who are now in troubles for buying a car with no factory support.

hanif001 -> RE: A6 Multitronic CVT judder (4/22/2007 2:11:17 PM)

Just a quick update on the CVT judder. After the additive treatment, I ran the car for a few hundred miles. After this I have changed the transmission fluid (dealer sourced) twice and now the juddering has almost completely dissapeared. Now there is no judder from most take offs (judder only occured during take off previously), some time on medium hard accleration there is just a very small amount of judder (which only the driver would notice).

I am hoping to change the oil one or two more times in the near future. CVT seems to getting better with each change. I am not certain whether the additive did anything? May be just the two oil changes may have done the trick!

I would recommend anyone with a CVT gearbox to get the transmission fluid changed more frequently than recommended by Audi. Eg, every 20k miles (instead of 40k) cos the oil change can be low cost preventative measure for what is an excellent gearbox. This is especially true with the high torque TDi engines where the gearbox can take full advantage of excellent pull power at low revs.


  

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