Please, for sometime now i am having a slight shift shock in my tranny when its shifting from 1st to 2nd and 2nd to 3rd gears. It happens mostly in the morning at cold start, but after driving for some 10 to 15minutes it becomes less or almost gone sometimes. The car moves good. I did changed my tranny fluid sometime in January 12, 2013 with high quality coastal multi-vehicle atf which is ATF M-V complaint. After which i drove it for like a month without any sign of the shift shock before i started feeling it (the shift shock). Recently, on the 16/03/2013, i had to drain and refill the tranny again with 7quarts of high quality Amsoil Synthetic Multi-Vehicle Automatic Transmission Fluid (ATF M-V compliant) which i order from the US. And also, i did had the tranny filter and tranny pan cleaned this time. I have done repeated diagnosis scan but there is no error code found. No check engine light illuminating on the dash screen. Despite all these, i am still having the slight shift shock. Please, i need your help or advice. Thanks

Car Details:
2007 mazda 6i 2.3L 5speed ATX

Wait, you used the coastal for about 2 months without any shift shock, why then drain and fill with another?

Sorry nissparts, i started feeling the shift shock after one month of changing the tranny fluid with the coastal atf. That was why i had to drain and fill again with amsoil fully synthetic atf to see if it might bring an improvement on it but it hasn't. Also, i have done repeated diagnosis scan but there is no error code found. No check engine light illuminating on the dash screen.

HAVE A MECHANIC JACK UP THE FRONT OF THE CAR AND CHECK YOUR ENGINE/TRANSMISSION MOUNTS

Ok. I shall do that this saturday and keep you posted how far i went. Thanks!

nissparts: HAVE A MECHANIC JACK UP THE FRONT OF THE CAR AND CHECK YOUR ENGINE/TRANSMISSION MOUNTS

@Nissparts: Was at the tranny/mech place today, checked the trans and engine mounts, all ok. Did a tranny and general engine scan for trouble codes, no codes found. All solenoids are ok, TCM is ok, PCM is ok too.

Most likely a computer upgrade required then.
I would live with it if I were you and to minimize it, let the car idle for about 30secs to a minute before driving off.

nissparts: Most likely a computer upgrade required then.
I would live with it if I were you and to minimize it, let the car idle for about 30secs to a minute before driving off.

Exactly what i am suspecting too because on some mazda 6 forums, some complaints with this issue had a system re-flash of their cars and it was solved. I would like to give a try of the system upgrade/ re-flash if it could be available in lagos. @ Nissparts; Please, do you have an idea where i can get a computer upgrade/ re-flash service done in lagos?

It's not a regular upgrade.
It's specific for the Mazda 6 and 3.
I sincerely doubt you can get someone with the particular software required.
Forget the mazda dealership here.

Hey Guys, i am having similar issues with my Ford Focus 2013. Done all the checks but transmission issue persists. Did some research online and found out that i may need some software update. I already contacted Coscharis the authorized dealer of Ford Motors in Nigeria but yet to get a response. Now, @nissparts do you know of any Auto technician that can do that for me in Lagos? This is an alternative arrangement that must be put in place, in case my dealership and warranty doesn't work for me. Thanks.

Can't say for certain but give me a call if Coscharis option fails