CVT rebuild

[MickyP64]

So the CVT on our W169 A200T finally gave up altogether!...I've been living in fear that day would come!

I’ve just got the car back after having the Gearbox and Torque Convertor completely rebuilt, so I thought I’d post the findings for others who may find themselves in a similar situation, as I’ve not seen this info posted anywhere else.

Forgive me, I’m not a mechanic but I’ll try to explain what our car has been through lately!

It seems that a common mechanical problem with the CVT found on the A & B Class (W169 & W245) is bearing/shaft wear on the Primary Pulley. Our car has done just less than 60,000 miles, and I’m told that 60,000 to 100,000 miles seems to be the danger zone for this issue.

You can see the Primary Pulley arrangement here - item B01 in this diagram:

The shaft and bearings between the Primary Pulley and the Primary Actuator wear - I’ve taken some photos of the resulting damage to the parts taken out of our car:






The result is that things begin to drift and not line up, and eventually in our case the Pulley/Actuator locked up and could no longer adjust the gear ratio resulting in the car going into limp mode and giving ‘ impermissible transmission ratio’ error codes.

This same issue also results in the drive shaft to the Torque convertor being pushed too far which also results in wear:



Very annoying!...This seems to confirm that some (maybe all?) MB CVT gearboxes appear to develop problems at around 60,000 miles, but comforting to know that you can actually get the transmission rebuilt, even if it is an expensive option (cost just shy of £2500.00). Unfortunately it seems quite possible that it’ll happen again in another 60,000 miles or so.

In addition to all this, I’ve learned that those suffering the dreaded speed sensor failure – you can now get a new ECU separate from the Valve Body which should allow for a cheaper repair. (Incidentally the guy that rebuilt my gearbox has used ecutesting in the past, and didn’t rate their repairs).

I also saw a video on Youtube recently (but can’t find the link – I think it’s one of the Mandy Conception, Automotive Diagnostics & Publishing vids). It suggested that no two CVT units are identical and need to be calibrated when installed – this probably explains why each new ECU needs to coded to the car when fitted.

I now personally feel that although the CVT certainly has problems, it’s not the scary beast I once thought it was. Hope this helps some folks out!

 

[wongl]

Interesting. Not heard that this is common problem prior to this posting.

Has the transmission fluid been changed on this CVT gearbox at the recommended schedule? And was the correct AFT used I wonder?

 

[GLK]

I've read a few complaints from Canadian W245 owners re same issue. Interestingly, many are from B200 Turbo drivers. Maybe it's just because they don't buy smaller engines, but could it be that CVT is not handling 2L turbo well?

I know that, for the W168 auto, it is best not to put car in D or R, until the revs go below 1000rpm (petrol auto), and wonder if something similar could be applicable to W169 CVT?

Mine is A200 (not turbo) and I'm on just under 33k miles at the moment, so this is an important consideration for me - I certainly do not fancy a £2,500 bill in a few years time.
ATF is getting changed as per MB schedule, in about 4k miles or 3 months, whichever is sooner. Anything other than that I ought to do?

 

[wongl]

I would suggest that you ensure that the ATF is sourced from MB directly as you are unlikely to achieve much of a savings buying the ATF from another supplier. Make sure also you get the filter in the gearbox replaced at the same time, and new seal is used on the sump pan.

Finally make sure that person doing the AFT is using the correct tool to check the level at the correct temperature.

If this is your first AFT change, I wouldn't leave it till the last minute. Get it change earlier if possible.

 

[GLK]

I would suggest that you ensure that the ATF is sourced from MB directly ...

Absolutely! The car is actually on Mercedes Service Care plan, so it'll be done by Mercedes.

Personally I would've preferred Olly @ PCS to do it, as he did for my old W168 (before it went onto a care plan too), but it's a bit frivolous to pay for something twice.

This next service will have quite a list of extra items due: brake fluid; air filter; combination filter; spark plugs and ATF. I'm certainly getting value for money on this plan!

 

[MickyP64]

Sorry, I didn’t mean to scare monger chaps!

I say common problem only that the guy that rebuilt my transmission has apparently seen a few of these now….and he described the problem to me even before I'd delivered the car to him! When I asked if this was a common problem with CVTs in general, he told me that amongst the problems that he sees with CVTs, he sees this particular problem most commonly on MB CVTs...I guess only time will tell really...

Until I owned the car it had always been serviced by main dealership - after I fell out with MB over the door rust that these cars also commonly suffer from I decided that I didn’t want to give any more of my money to MB, so have since always had it serviced by Wright Tech (my closest MB indie). Of course indirectly I’ll always be giving a portion of my hard earned cash to MB…but the less of it that they get their hands on the better in my opinion.

Anyway I can’t be fully certain of course, but as the car has been serviced either by MB dealership or reputable indie, I’d expect that the correct ATF has always been used on service.

I too have wondered if this is a problem most seen on the turbo models…

 

[GLK]

He-he ... you too? - I've submitted a request to MB to rectify the door rust (on the inside!), but was turned down. The car was always serviced by main dealer ... ah, well. What can you do.

Have you fixed it, by the way? My american colleague suggested I just "araldite 'er ass" and be done with it ... I'm considering it

 

[John]

so have since always had it serviced by Wright Tech (my closest MB indie). Of course indirectly I’ll always be giving a portion of my hard earned cash to MB…but the less of it that they get their hands on the better in my opinion.

I saw a black A200 turbo there the other day (last Saturday I think).

I wondered if it was someone on the forum!

Might be a different one mind.

 

[MickyP64]

That’ll be ours!...There aren’t many about…

I believe there’s only about 170 left on the road in the UK (well CVT version) and about 60 manual ones…MB only made them for about three years….probably because the whole idea of a turbo A Class is arguably an ill-conceived idea ...I guess if you wanted that much power in a small car you’d probably go for a Golf GTI instead…but they’re so common

Because it’s such a rare car I’m inclined to try to keep it going…not because I think its rarity adds any value (probably the opposite) but because the Mrs and I quite like it…well she liked the A Class and I said if we get one I want the one that has some b*****ks!

 

[MickyP64]

He-he ... you too? - I've submitted a request to MB to rectify the door rust (on the inside!), but was turned down. The car was always serviced by main dealer ... ah, well. What can you do.

Have you fixed it, by the way? My american colleague suggested I just "araldite 'er ass" and be done with it ... I'm considering it

There’s a reasonably long thread that I started about this when I first joined the forum for advice.

The upshot – MB offered me 50/50 on good will, it would have still have cost me something like £3600.00 and they wouldn’t budge. Did consider small claims court but lost the energy to continue.

What I have done is to source replacements for all five doors in the same colour from crash salvage – making sure that they come from later model cars. Mine come from two different 2011 A Class cars (Avantgarde or Excellence model so I get the trim too). They’re still sitting in my garage waiting for me to find the time to fit them…

You need to look for cars that have been rear or front ended...Cost me about £800 (and nine months of searching online) for a full set of very good condition replacement doors - with the newer style seam seal (except the tail which still appears to come with the old rubbish even on the newer cars).

 

[GLK]

Thanks, I'll look into that.

The problem is my A200 is a coupe, so pretty rare, although I've seen a few A160 and A180 facelift 3-door versions for sale, so there must be some at the breakers too...

 

[MickyP64]

You're lucky, you've only got to find three doors!

I needed five...When I started looking I found the two rear doors and tailgate quite quickly, I then spent the next nine months searching every online salvage yard and eBay for two matching front doors...I sourced them from Germany in the end...I drove over to collect them!...I must be mad...

If you decide to go this route make sure you view before you buy if you can...even better if you can collect them yourself as you'll probably take more care of them than any salvage yard guys or couriers would.

Colour match is something else to consider...your paintwork is likely to be older than that of the doors you'll source, it's quite possible I might find this to be a problem when I come to fit mine.

I thought all three door versions were coupe?...

I also saw a comment on a thread somewhere (not sure if it was here or the other forum)...guy said that he has the later type seam seal on his car doors and even that was showing ominous signs of rust!...I guess time will tell eh...

Good luck...

 

[GLK]

Yes, the 3-door version is a coupe (C169).

Not sure I'm prepare to spend that much money, and effort, on dealing with this rust, particularly, as you said, people been reporting even new type of seal is rusting too (I think I saw something on BenzWorld).

I'll probably just remove, clean/treat and glue back the entire wobbly seal ... as mad as it sounds.