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2.7HDi V6 Auto Gearbox Jerky Shifts
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David K   
Mon Aug 04 2014, 09:28pm
Joined: Jan 30 2010
Member No: #42
Location: Scania
 I have to say I'm deeply impressed by your enthusiasm and encourage to solve your issues with your C6. You must have had every single possible issue that a C6 can offer by now, and still you just solve the problems and continue to love your car.

So a big thumb up for you smihaialex and good luck with your oil change!
magicands   
Tue Aug 05 2014, 02:29pm
Joined: Sep 13 2012
Member No: #1021
Location: Coventry, Warwickshire
 I agree with the above completely.
I never knew that I lived in another world with my Vauxhall Omega as it never gave me any serious problems throughout my 10 year ownership, and yes, it never had an auto box oil change in all that time.
Strikes me that the C6 limps from one EXPENSIVE disaster to the next and yet people will resolve the issues as and when they appear because, and I don't think I am wrong here.......we all own a car that very few people ever see on UK roads?
Website
Kaloteck   
Tue Aug 05 2014, 05:04pm
Joined: Apr 25 2013
Member No: #1271
Location: Warsaw
David K wrote ...

I have to say I'm deeply impressed by your enthusiasm and encourage to solve your issues with your C6.

Hey, what did you expect, it is love, that's what it is

joaoproenca   
Sun Aug 17 2014, 04:16pm
Joined: Dec 05 2013
Member No: #1510
Location: Portugal
 From what you describe is a problem on control valves nothing to do with ECU. ECU barely broken and if so you can rebuild it consult this company - Click Here -
yellowtextmarker   
Tue Sep 09 2014, 08:58pm
Joined: Sep 09 2014
Member No: #1855
Location: Deutschland
 As an oil change just changes a portion of the fluid you might check for companies which can change 100% of the fluid AND clean the gearbox. In Germany such garages are available for the boxes used in our C6 - check this link and try to find your solution: - Click Here -.

Good luck and drive! Yellowtextmarker
smihaialex   
Fri Jan 09 2015, 09:32am
Joined: Sep 18 2012
Member No: #1031
Location: Bucharest
 Thank you for your kind words and recommendations guys... Yes! It is love... Without a shadow of a doubt

I've been trying to find a company that does auto gearbox flushing in Romania, but so far to no avail... And driving to Germany for this is not really an option right now...

I'll keep looking and in the mean-time do another set of 3 partial oil changes...

I'll also be sending the instrument cluster to BBA Reman for repair...

Other than that, I just had my C6 go through the 2-year mandatory technical inspection and everything is OK - not even minor notes...

In March I plan to change brake fluid, coolant fluid, oil, filters, brake pads & discs (if necessary), and also fit new windshield wipers... and, if necessary, do a 3rd set of 3 partial ATF changes, and I should be good to go for another 1-2 years

Yours,
Sam
gmerry   
Fri Jan 09 2015, 11:18am
Joined: Dec 11 2009
Member No: #21
Location: Scotland
 Sam, don't discount the value of doing multiple changes as you are planning (compared to a flush change).

So long as the car is run up to temperature between each partial change, you will achieve practically the same result (ie dilution of wear particles and restoration of the fluid viscosity and friction additive) at a cost of the fluid alone (assuming your own labour is free). Also, doing it yourself, you are totally in charge of cleanliness and introduction or not of any foreign dirt.

Regards
G

PS, the term flush is a bit of misnomer when talking about hooking up to an external oil change machine. The internal flow velocities/temperatures within the box will not be any different hence it is not really a flush.

PPS here's the dilution status after each partial change

Oil Dilution Status
dirty (litres) clean(litres) % dirty
beginning 7 0 100.00%
after 1 change 4.1 2.9 58.57%
after 2 changes 1.698571429 5.301428571 24.27%
after 3 changes 0.703693878 6.296306122 10.05%
after 4 changes 0.291530321 6.708469679 4.16%
after 5 changes 0.120776847 6.879223153 1.73%
after 6 changes 0.050036122 6.949963878 0.71%
smihaialex   
Tue Jan 13 2015, 01:16pm
Joined: Sep 18 2012
Member No: #1031
Location: Bucharest
 Thanks G,

I did a lot of research and you are right - when I initially heard about the flushing technique I thought it involved running of some cleaning fluid at high velocity through the gearbox, but in fact it just involves sucking the old fluid via vacuum and pumping in new oil - not a lot of actual flushing, but it does save some time

Cheerios,
Sam
gmerry   
Tue Jan 13 2015, 01:41pm
Joined: Dec 11 2009
Member No: #21
Location: Scotland
 Hi Sammy, correct. The only thing it saves is time, which equals money if you are doing these daily and making a living from it. That's why an auto shop will use a machine.

If you are capable of doing the job yourself, it then comes down to cost (ie cost of driving to the shop, plus paying for the job versus your own time value).

For me, the cost/time of driving to a shop far outweighs my own time value of doing the job. In addition, I'll schedule in some other maintenance while I'm doing this job (oil change, air filter change, fuel filter change) so making most use of my time. If I had a shop on my doorstep that I was 100% happy with regarding fluid cleanliness/hygene, I might reconsider.

Please note that the machine just fits in place of the oil cooler (which is only a bypass device anyhow, so a flushing machine cannot achieve 100% fluid changeout either).

Regards
smihaialex   
Tue Jan 13 2015, 02:26pm
Joined: Sep 18 2012
Member No: #1031
Location: Bucharest
 Anyways, after my last post I started searching again for specialized auto gearbox repair shops and this time I found three...

I called each and everyone of them just to get a feel for their expertise:
  • have they done C6s before?

  • have they done Aisin Warner gearboxes before?

  • what's the ATF that they use for this gearbox?

and surprisingly they all have done C6s, they know AW boxes very well, not necessarily from C6s, but from Peugeot 407s, Opel/Vauxhal Insignias, Volovos etc...

What I found out was very surprising to say the least:
  • one of the 3 guys knew that Comma ASW was the best ATF for this gearbox

  • another guy had owned a 407 with the same gearbox and the same problem himself - he described to me the problem like he had driven my car - normal running when cold, but when hot, gearbox hunting and slipping between 2nd and 3rd (engine revving), small shock on 3rd gear pick-up and big bump on stopping and putting the gearbox in reverse...

  • he told me that the gearbox in our C6s is AW TF-80SC also known as AWF21, AF40-6, AM6 or AW6A-EL, but internally referred to by Aisin as TC80/AF40

  • he also told me that there is no way that I'm getting out of this without changing the hydraulic block, regardless of how many partial ATF changes or flushes I do

  • he explained to me a simple rule of thumb - if there's just shock - no hunting and no slipping - then yes - you might get away by just replacing the ATF 1-2-3-4-5 times or doing a complete flush and get away with a couple more years out of the hydraulic block before replacing it...
    if there's slipping and hunting then you have to change the block... That's the bad news

  • the good news is that for this particular gearbox, just changing the hydraulic block will most likely fix everything

  • if it were a Merc or BMW with the same symptoms, then just replacing the hydraulic block wouldn't fix it - you'd also have to recondition the box itself - replace the set of gaskets, some pistons, because in a Merc or BMW a shot hydraulic block would just produce shocks when changing gear, no slipping and no hunting, and if it slipped then it would also require reconditioning for sure, but in a TC80/AF40 it doesn't

  • and last but not least, and possibly the most interesting and useful information for all you smart DIYers out there, you can do a complete flush without a flushing machine - you just have to do manually what the flushing machine does automatically, and the car itself will help you (some flushing machines use a vacuum pump to suck out the used ATF, but they are not very reliable, just like G says - there is no actual guarantee that it takes all of the old ATF out, in fact it most likely doesn't - most flushing machines however use the new oil to push out the old oil, and the good news is that you can emulate that, by using your car, gravity, and some clever timing- start the car, heat the ATF to 30-50 deg. C, let 3-4 liters out, dismantle the radiator's return pipe, pour in 3-4 liters of new ATF, start the engine, and collect the used oil coming out of the return pipe, rinse and repeat- you'll need at least 10 liters of new ATF to take out the old 7 liters from the box and have 7 liters of new ATF inside when you're done)


Bottom-line:
  • I've got 12 liters of Comma ASW in the trunk

  • Thursday morning I'm taking the car to them and replacing the hydraulic block for a brand new one Aisin Warner AF40 (1 year warranty)

  • The cost of the Hydraulic block is 806 EUR (less then half of what Citroen charge)

  • The cost of the labor, including complete ATF change is 120 EUR (three times what Citroen charges just for a partial ATF change)


And after that, I will have a brand new gearbox, slip, hunting and shock free, hopefully...

If not, reconditioning the gearbox is a whole new headache - almost 2000 EUR but hopefully that won't be the case...

What do you think?

Cheerios,
Sam
gmerry   
Tue Jan 13 2015, 02:47pm
Joined: Dec 11 2009
Member No: #21
Location: Scotland
 You are on the right path.

Regards
G
cruiserphil   
Tue Jan 13 2015, 08:22pm

Joined: Jan 24 2010
Member No: #38
Location: Celbridge
 Sam,
Nice info. Many thanks.
Phil C.
gmerry   
Wed Jan 14 2015, 01:51pm
Joined: Dec 11 2009
Member No: #21
Location: Scotland
 Hi, for UK forum members, Sussex Auto Transmissions has brand new AM6 valve bodies in stock at less than £500 plus VAT.

There are various tricky aspects to removal of the old body and replacement by the new, especially with regard to disconnecting the manual valve and refilling the valve body with fluid. So make sure you choose your shop/technician with care.

There is also a need to reset the ECU back to new condition so that the transmission can recommence the learning process *it will have been compensating for valve wear*

Regards
G

One aspect that emerges is that a lot of the valves are dynamic, operating at 300Hz so there is a lot of wear potential.
smihaialex   
Thu Jan 15 2015, 01:06pm
Joined: Sep 18 2012
Member No: #1031
Location: Bucharest
 Gentlemen,

I'm happy to report that the car is in the shop as we speak...

The prices are similar, my hydraulic block cost 650 EUR + VAT which is almost exactly 500 GBP + VAT

Another piece of info - on Volvos and Insignias this gearbox has a flow pipe and a return pipe and it uses the car's radiator for cooling, but on the C6, as well as on the Pugs there's a small dedicated radiator mounted on the gearbox itself, no pipes... This means that you can only do multiple partial changes, if you don't want to take the radiator off the gearbox...

I'm going to go get my car back in one and a half hours or so and I'll report back with the first roadtest results.

Cheerios,
Sam
David K   
Sat Feb 07 2015, 01:04pm
Joined: Jan 30 2010
Member No: #42
Location: Scania
 How did it work out?
Any improvement?
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