Clunking shifting from R to F in 2012 CX-9

There is a loud clunking sound that happens intermittently when shifting from Reverse to Forward in my CX-9.

It doesn't happen all the time, but I was finally able to catch it on video. The engine lurches quite a bit, which rather surprised me. Attaching the video here, sorry for the quality but I had to reduce the size to post it.

Any thoughts? Is this a transmission problem, possibly TCM? Or is this what it looks like when motor or transmission mounts start to go?


  • CX-9 Transmission.mp4
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2010 CX-9 GT
That looks like a broken mount. Some motion is normal, but that looks excessive.

If you put it in neutral and rev it a little and the engine rocks back or forward more than a small amount, that's another sign.
Update on this. Looking at a few more things here it does not appear to be the mounts.

There are a few TSBs out there on "Shift Shock" for CX-9s, and while they did reflash the TCU a year or so ago the problem appears to have returned. One thing I worry about is that the TSB says that certain TCUs can't be reflashed, only replaced. So, I will have to see if the dealership performed the correct service or not. Bringing it back in later this week.

Has anyone else seen/experienced something like this? I wonder if there could also be something problematic with the transmission fluid. It frustrates me to no end how these vehicles were manufactured with "sealed for life" transmissions and power transfer units/transfer cases.
I had a similar clunk recently on my 2013 and it turned out to be the transfer case failing. I also had a high pitched whine at 60 and 100km/h. The down shifting was also slightly clunky at times. Luckily, I still had 6 months left on the factory extended warranty for that part.
I took the vehicle to the dealer and they performed an adaptive shift re-learn which appears to have fixed the problem. Previously (1 year ago) they did a TCM upgrade per the service bulletin on shift shock (TSB 05-009/16) so we will see what happens with this latest fix. It's a good reminder that going to Mazda for things like this is best, as only they have the computers that can do this work.

It definitely appears to be something with the TCM putting too much torque at certain times when changing from reverse or neutral to drive. It only happens when the car is at operating temperature. It felt like someone applying a little throttle when shifting into drive, even though it is at idle.

Hard to say if a failing transfer case is making the problem worse. This vehicle is on its second one already (first replaced in 2015). Definitely a bad Ford design there, which I guess they realize as the newer ones have drain plugs on them. It's a shame because the car has held up quite well all things considered. If anything major ever happens with the transmission though, the car will have to be junked. Fingers crossed.
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Yup, I tried to extend the life of my TC by having the dealer change the fluid every 30K kilometers (sucking it out the top) and it still failed at just over 100k. However, I always had a whine around 100km/h, so I realize my unit was a bit wonky right from the start. The whine at 60km/h just started this year. Otherwise, the car was super reliable!

Just replaced it with a 2021, which thankfully has no Ford parts!