I have a 2017 Mazda 6 with 79k miles, recently it’s been a bit harsh with the shifting especially downshift. Notable thump sometimes clunk between R and D. Also sometimes clunks when the car comes to a stop when was in motion. With the Mazda procedure to forget driver habit (tcm) does help but problem usually returns but last longer with conservative accel/decel. Mounts and suspension look good but the way the engine looks kicking into gear would lead someone to assume they are bad. Also no codes. Any ideas to what the cause of the issue? Could it be electronic?
First check things like transmission mounts and drive shaft joints they'll often wear and cause such clunking. Rarely. Is that stuff electronic? It's normally a physical problem of something worn so pray it's not inside the transmission with worn gears
@scottykilmer the car was a rental for the first 20k of its life, idk seems still a little premature at 79k. Have replaced mounts and axles. Axles both boots tore, tranny mount gave others were fine but replaced all. Might have to bite the bullet , should I take it to a shop to try and diagnose it or just install a used one.
should I take it to a shop to try and diagnose it
Scotty doesn't usually revisit topics he has already answered.
It would not be a bad idea to take it to a good independent transmission shop that can record and analyze transmission data using a high-end scan tool. (Stay away from dealers and and chain shops.)
@chucktobias thank you chuck but I have some good news at least, I dropped the pan swapped the filter and refilled with atf mfz. Surprisingly improved the trans performance, scared it’s gonna come back(no longer harsh or clunking). Probably gonna drain and refill a couple more times, to have newer fluid in the tranny as it did fix my issues.
@chucktobias the results weren’t immediate. Happened over some miles.
@mrbusdriver Sounds like a lucky break! Clean fluid can definitely help as long as the trans hasn't gone so long without maintenance that friction surfaces are damaged.