2008 Mazda CX-9 AWD Testing


I have a 2008 Mazda CX-9 that I've owned about a year. I took it in to dealer for brake work. They tell me that there is no power to the AWD and that the rear drive shaft isn't turning. They quote $4,500 to replace the transmission and PTU and ask if I want to move forward with the brakes since it has this other more serious issue. I hold off on any work.

I take it in to a well reviewed/recommended local transmission shop for a 2nd opinion and competitive quote. After a $100 diag fee, he says the transmission needs maintenance fluid change, but that the AWD is fine and transmission is operating within specs and that there are no error codes.

How do I tell which one is right?
well i don't know where you are but have you tried to see if the awd is working? Try to find a slippy surface and do a quick acceleration, if one wheel spins and you get a flashing awd sysmbol in your dash then the awd doesn't work.

If the car is on the lift and they put it in drive and the main driveshaft is not turning then yes you have a problem with either the transfer case of the splines of the transmission. Read the threads in this forum, plenty of info about it.

If you don't use the awd then just drive it like that and forget about it. If you don't live in a climate with snow, you won't really need it anyway.
92 MX-3; 18 CX-5
I would trust the transmission shop. Definitely have them replace both the transmission fluid and PTU gear oil. The PTU is the weak link. With only 1/2 qt of gear oil inside that is constantly being cooked by the exhaust. The result: The PTU bearings get cooked, create a huge load and take the transmission out.
For the transmission confirm that they use the correct fluid (Aisin WS ATF for 6 speed tranny) and only drain and fill the transmission. Avoid a flush.
The PTU uses 75-140W synthetic gear oil. Ford makes some magic stuff (nice label and expensive) but any high quality gear oil of the same viscosity should work. The bugger with the PTU is that you only have a fill plug that is nearly inaccessible. You have to pump the heavy gear oil out and then add new fluid to just overflow the fill plug hole.