Hey folks,

Got a pretty silly question but need your help. I’m a good driver but bad car owner🥲

Mazda 3 BM 2016 1.5 automatic 

Today had my first change of the transmission fluid at around 64.4 k miles.

Not due to any issues but mainly a long missed due time.

Was watching the process:

\- used fluid was dark-red with a definitive burn smell

\- a magnet near the filter collected lots of metal parts (I assume smaller ones) - see the image above

\- got around a gallon used fluid out; though, it was not enough when pouring in a new fluid (seems needs around 1.25-1.5) - I assume a part of used one vaporized over time 

\- software did not show any errors (except for some non-related due to the battery)

To confirm, not sure how much time I had this low-level/quality fluid. 

At some point, I noticed when I was switching from P to D or R, some additional resistance was there (as if I parked on the hill and want to switch).

So the silly question is - how bad this can be for the transmission and what is the best way to evaluate without disassembling it?

Or would you rather recommend driving while paying more attention to the behavior (slipping, noise, etc.) and not missing next maintenance ever again?

Transmission Maintenance Question