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How reliable are auto cvt boxes?

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by p1tse, Jan 21, 2011.

  1. p1tse
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    p1tse Member

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    Looking at tdi models, are the cvt problematic as I remember when looking at b7 versions people mentioned multitronic has higher failure rate than tiptronic found in quattros

    Are b6 cvt same as b7 multitronic?
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  2. donsajid
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    donsajid Member

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    as long as they are regularly maintained, ie. change the trans oil every 20-25000 as opposed to dealer recommended 40000 miles. I don't know if they are the same as the B7, but i seem to remember reading that they changed them after 2008 so most probably same. Also worth checking if the box has had the seven plate clutch upgrade as this can prolong the box.
    Very expensive to put right if you do have a problem, look out for slight judders at low revs, and the car rolling back on a steep hill whilst in drive. A little roll is OK, but if its rolling a lot then chances are the box is showing signs of wear.
    On the plus side, one of the best driving experiences you will get from an auto box. Silky smooth gearchange, and coupled with the v6 2.5tdi just an absolute dream to drive.
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  3. CHRIS555
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    CHRIS555 DOPE with added OCD

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    Unfortunately I have only ever heard bad things.........
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  4. Jine
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    Jine Crippled n Crazy

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    I have a CVT in mine, and i haven't had any problems (Just jinxed myself now)! Keep it serviced at regular intervals and all should be fine. Just 1 thing, they can be pretty lazy on a fast pull away from the lights or junctions.
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  5. BahnStormer77
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    BahnStormer77 BahnStormer

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    There was a complete Audi recall on all auto, FWD (i.e. CVT) 2.5TDI's and there was such a high failure rate on the others, mostly 1.9TDI's (and also the 1.8T's) that Audi paid a large portion of the £1500-£2200 repair bill to convert from 6-plate to 7-plate clutches. I believe that this "goodwill offer" only applied in 2005-2006 and now varies tremendously from dealer to dealer. Given that this problem normally occurred between 30k and 60k, I think Audi's line is that anything that fails after 5yrs or after 60k can't be blamed entirely on a design fault.

    The 2.0FSI's don't generate enough torque to cause a problem and (unless remapped) the 1.8T's are supposed to be okay-ish: it was mostly the TDI's and remapped 1.8T's that were a problem.

    Not entirely certain if there were any other changes along with this overhaul but the CVT fitted 2.0TDI A6's had significant "reliability related" change mid-2007 to make the CVT boxes last longer. Not sure exactly when this was applied to the A4 though.

    Personally: I think the CVT boxes are fantastic, as do most people who own them (until they go pop), but unless there was an Audi invoiced 6-plate to 7-plate clutch conversion (that you could verify with that Audi dealership), I wouldn't touch any turbo-charged (high torque) engine with a CVT gearbox.

    To back up the fact I'm definitely NOT anti CVT: 2 yrs ago, my dad was asking which car to buy as his daily commuter (and declined my first suggestion of a fully loaded A6 2.7 Quattro Sport - albeit with starship mileage), I then recommended a late 2007 CVT 2.0TDI which he thinks is brilliant.
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  6. Stuforce
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    Stuforce New Member

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    Hey guys, I'm getting a slight juddering in the same spot when doing 40 to 50 mph in 5th gear, at around 1500rpm. This is the only time it seems to happen at the moment... Do you think it's on it's way out?

    Also the turbo sounds a bit crook, not such a smooth whistle as when I bought it a few weeks ago! Lovely car to drive, I just want to make sure it stays that way as long as possible.

    Any ideas or advice would be great, thanks .. Should I take it to a dealer and get some diagnosis? I heard its possible to update the cvt controller software ...

    Stuart

    The car is an avant 2.5tdi Quattro sport auto 2002, just over 60k..
    #6
  7. BahnStormer77
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    BahnStormer77 BahnStormer

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    If it's a 2.5TDI Quattro, then it's NOT a CVT (constantly variable transmission) auto-box, it's a regular automatic (torque converter).

    The load on the clutch + gear box is a product of the amount of torque the engine has and the grip: When you have quattro grip + V6 TDI, it means that the clutch + gearbox is stuck between a rock and a hard-place.... Audi have never put a CVT in a quattro, ever. CVT's have eveolved and got a lot better (especially since 2007), so I'm sure there are some additional technical reasons why they m and the clutch is holding ight have trouble getting the drive to the Torsen differential, but even the latest A6's and A7's with the 3.0TDI have Tiptronic (regular auto) on the quattro's and CVT on the FWD versions...

    1500rpm is your peak torque, so if you're going to see early signs of the clutch going, then this is when you''d get it.

    This is an adaptation of the manual test for a worn clutch, so the auto-owners feel free to correct me on this: but I would suggest to try forcing the gearbox to hold up a gear while getting the turbo to spool up (not even sure if that's possible on an Audi auto, the last "old" automatic Audi I drove was an 80 Cabriolet!).

    If it will hold onto a gear (e.g. 4th/5th), while the turbo spools: then the revs should climb steadily with the speed. If the revs slip up in a series of juddering blips while it stays in the same gear, then the clutch isn't holding.

    If the juddering is due to it hunting around the box for the right gear, then a softwar fix might help, but NOT if it's for a CVT box ;)
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  8. Mike B
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    Mike B Member

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    I have same model but 04 with 115k and never had any juddering.You might find an ATF change helpful.Its not supposed to be necessary but some say it cant stay 100% and it was done on mine last year.I think its been even smoother and worth doing at this sort of mileage
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  9. BahnStormer77
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    BahnStormer77 BahnStormer

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    @Mike: StuForce's is a quattro, so not CVT.
    Last edited: Oct 3, 2012
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  10. Stuforce
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    Stuforce New Member

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    Thanks gents, good advice!

    Happy that its not a CVT now, as I've heard some bad things- about an Audi free recall to fit a 7 plate clutch?! Sounds expensive if our of warranty( just!) 60430 miles

    ! Lostboc, I'll try the tests you mentioned, and update..

    Cheers
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  11. BahnStormer77
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    BahnStormer77 BahnStormer

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    yep, fairly expensive: £1500-odd to fix the problem if it was a CVT and if not covered by the recall... so about the same as a cambelt + waterpump at some Audi dealerships ;)

    The "test" for manuals is the put the car in 5th at about 40mph and put your foot down to get the turbo to spool up from low-ish revs and accelerate through the peak torque (around 1500rpm iirc) and to see if the revs increase at the same rate as as the speed or if you get any little srges: might need an observer / VERY empty road! The concern for auto's is that I think that if you push your foot to the floor, it'll "kick-down" (i.e. change down because it can sense you want to accelerate hard)... I know that's what most auto's do, but hopefully there's a way to accelerate hard without triggering the kick-down....
    #11

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