CX-9 2013 GT AWD - Shudder in drivetrain

Hi folks,

My local official Mazda service centre has diagnosed a shudder in my drive train as requiring a new Transmission and Transfer Case / PTO / PTU, at a cost of $19K AUD. I've read the forums and understand this is a known design flaw / defect with this generation of CX-9 AWD, due to Mazda's decision to not add these to the Maintenance Schedule nor add a drainage plug. My local Auto Transmission mechanic though disagrees with this and says he knows about the defect with the Transfer Case, and doesn't believe this is the same issue, instead saying it is the Torque Converter, and maybe also the Coils / Solenoids.

Can I get some help from the kind folks on this forum in diagnosing?

Symptoms:
1) A strong shudder / vibration in the drive train at certain RPMs, typically when power comes 'off'. Occurs only in 4th, 5th and 6th gears. Can be 'remedied' by either taking your foot off the gas or putting it firmly on. Can be prevented by driving in manual gear shift mode and staying out of the RPM bands where it occurs (1500-1700 RPMs, and sometimes around 2400RPMs).
2) A slight /soft jolt sometimes on gear change, hard to detect and doesn't happen all the time.
3) A perceptible cyclic noise at some speeds from the wheels, slight whoosh whoosh whoosh, fairly fast (2 or 3 whoosh per second).

From what I've read if this was the known Transfer Case issue, it wouldn't be addressed through driving in manual gear shift mode.

Many thanks for your insights.
 
doesn't sound like transfer case but have you done the obvious? change the plugs or the transmission fluid? Do you have any codes?
 
Hi Puma, thanks for the reply:

* Change the plugs - no not yet, another mechanic was given this information, and said it was definitely not the problem. But as I understand this is relatively cheap, it may be worth doing just to eliminate it as a possibility.

* Transmission fluid - yes, this was replaced (two flushes) and the Transmission serviced by the Auto Transmission place, but this work did not address the issue. If anything it feels like the shudder (symptom 1) is stronger / more frequent now.

* Any codes - no codes have been reported by Mazda service centre or any of the other mechanics I've taken it to
 
The shudder is definitely from the torque converter. And the shifting problem could be from the transmission solenoids becoming a bit sticky. I had the same problems one year ago. I solve it by adding one "Lubegard shudder fixx" and "Lubegard Automatic Transmission Fluid Protectant 10 Oz." to the ATF with warm engine than driving for 10 minutes after. And it did the job. Try it and I hope it will work for you to.
 
I'd bet the plugs. Had the exact same issue. Was ready to change the torque convertor but took a shot at the plugs. Fixed the issue. Symptom was coasting at freeway speeds, then give it a little gas and it felt like the torque convertor delayed locking up.
 
:
2014 Ford Explorer Sport, 2009 CX9(Wife's)
I'd bet the plugs. Had the exact same issue. Was ready to change the torque convertor but took a shot at the plugs. Fixed the issue. Symptom was coasting at freeway speeds, then give it a little gas and it felt like the torque convertor delayed locking up.
Same with my wife's 09.
I was thinking it was transmission/torque converter, but after some OBDII reader analysis, found it was getting a misfire on a couple cylinders. Replaced plugs and issue went away.