In 2018 I decided to do a gearbox flush at the non dealership cause I had been experiencing harsh and delayed shifts (a "BANG" sound comes often but not every time as the box s**t gear and the car shakes for a second) between the 1-2-3 gears both up and down for a few years already (the car had a mileage of 260000 km at the time of the flush and oil change and that was the first oil change since the car was new) and after the flush and the 3309 oil change the gearing was smoother for about 2 weeks - then it went back to being harsh again and possibly worse this time. Well it has not improved since. And I have spent 7 years trying to figure out why the gearbox acts this way.
Some say I need to replace the valve box. But recently through the use of GROK I have been able to discover that the 3309 oil might be the wrong oil for my AM6 gearbox which might be the second version of AM6, also known as the AT6 gearbox by PSA. The symptoms have been getting worse this year. The car is vibrating while idling, but the intensity of vibration changes a little when switching between P, R, N and D. It's sually best to put the car in N while idling, then back to P. It´s weird but this makes me as a non mechanic (but Citroen loving) man belive these symptoms while idling comes from the gearbox. The car engine also gets louder while in idle, but that might just be vibrations. Which brings me to the sticker on the gearbox ECU (I believe that´s where it's located) that I took a first time ever look at today (yes I know, that took way too long...).
I will now post a picture of this sticker and I am 100% sure someone on here will be able to confirm wether this is the first AM6 which uses 3309 or the second gen AM6 (AT6) which uses AW-1 oill. I have already bought the AW-1 oil, but I don´t want to change oil on the gearbox before I am 100% sure which gearbox this really is. How many people on here have gone through the same AM6 and oil-confusion as I am in the middle of right now?
And for those who don't want to read my longish post up there: Which AM6 version is this gearbox pictured below - the first version called AM6 or the second version called AT6 by PSA?
When I know exactly which gearbox this is I also know which gearbox oil to fill on this gearbox! I am afraid I have been running the wrong oil in my gearbox for 7 years since the last flushing and refill. (3309 oil)
Best Regards,
Tom
UPDATE a couple of hours later this night:
I´ve been talking to GROK for a while now and GROK says some interesting tings. I don't know if they are true but here goes (for evidence I have the second AM6 box, the AT6!):
“CEMI” on the gearbox sticker is irrefutable, 100 % factory proof that you have the AT6 / Gen 2 TF-80SC that requires AW-1 / JWS 3324.That single word “CEMI” is PSA’s own internal code that only appears on the updated 2006–2008 AT6/AM6-2 boxes — never on the early AM6 that used 3309.Official sources that explicitly state this:PSA ServiceBox bulletin (mirrored on FrenchCarForum)
“AM6 CEMI (Euro 5 transitional, 2006+ facelift) = JWS 3324 / AW-1.
The oil type ‘AW-1’ in AT6 and AM6 gearboxes with CEMI designation is specific and cannot be replaced with JWS 3309.”
Aisin ATF Application List (official PDF, page 3)
“TF-80SC Gen 2 – PSA applications with CEMI variant – serial 12xxxxxx = ATF AW-1 / JWS 3324 only.”
DiagBox screenshots from dozens of 2006–2007 C5/407 owners
Every single car that has the sticker text AW_BVA_AM6_CEMI shows AT6 and fluid 9734.R7 / 9979.A7 (AW-1) in the factory database.
There is no documented case of a CEMI-tagged gearbox ever being spec’d for 3309.
Zero.
It simply does not exist.So when you walk in with your photo and say
“Here’s the sticker – it literally says CEMI. That means AT6 = AW-1. End of discussion.”
they have nothing left to argue with.CEMI = AT6 = AW-1"
