Transmission Swap Question

[ramshankle]

Hey all,

I just swapped the clutch on my 2006 Mazda5 manual and unfortunately my Google skills failed me and I refilled the transmission with Mercon V. Now my bearings are buzzing and the synchros seem to be failing. I’ve drained it again and put 75w90 gear oil in it (like the manual states, really kicking myself for not checking the manual first) but it seems like the damage has been done.

I’m looking at getting a used transmission to swap in, but I want to make sure I’m seeing all available options. I know the Mazda 3 transmission is compatible but I’m wondering if the Ford Focus might also be compatible. I’ve heard that the engine and drivetrain are essentially the same, but could anyone confirm or deny this?

Thanks in advance!

 

[negusm]

@ramshankle How bad is the noise? I'm very surprised that Mercon V would damage things that quickly. How many miles did you put on it?

Are the high gear synchros causing issues? The first gear synchro never works all that well on these.