06 Mazda bad noise and jerk in 4th gear

we have an 2006 Mazada 6 automatic transmission with the option of manually shifting gears. we have had it a year and the only maintenance is work on the air conditioner, oil changes, and new tires. when accelerating on an incline or sometimes during/after a curve as it shifts into 4th gear it makes a terrible noise and the whole car jerks. the best way I know to describe it is it feels as if the bottom of the car is about to fall out! when we first purchased it, it done this a couple times and basically quit doing it for a few months. it seems to be getting worse though. we have never had a check engine light. we sent a can of “sea foam” through the gas tank and this seemed to help. a local mechanic examined it and test drove it but couldn’t find anything wrong with it. (of course it didn’t act like this when he drove it!) I called mazda dealership and they cant tell us anything without us bringing it in and charging us no telling how much just to look at it. no one seems to be able to figure this out…. has anyone experienced anything like this before? please help!!!

Check the engine mounts (especially front and rear) and see if you can find out the last time the transmission fluid was exchanged. If it’s been more than 50k miles, or you can’t find the information at all, have it changed.

How many miles? Is trans actually shifting badly so it makes noise? Newer cars are all about smoothness, quiet, and so on. If u grit ur teeth during these shifts, than it is probably not a minor issue. My friend had his trans issue fixed by replacing torque conv and valve body under warranty. Big deal but he had warranty. Dealer said that was easiest way to probably fix it. No kidding.

Unfortunately this is known issue with Mazda 6 trannys that requires replacement of the tranny with a redesigned one. Check your VIN against the VINs listed in the answer below to verify.

2006-2008 Mazda6 vehicles with VINS lower than 1YVHP******M39067 (produced before March 4, 2008)

Make sure you get an updated transmission. The updated transmission is Mazda part number ZP4K-19-090R-0A. You might be able to find a used one to save $$ but you must verify it is the updated one.

Very often, drivability problems that people attribute to a transmission are really the result of engine issues. However, in this case I think that an engine problem is less likely than the aforementioned possibility of broken motor mounts/transmission mounts or an internal transmission issue.

If I was in this situation, I would do the following:

Immediately check the level, color, and odor of the trans fluid
If it is low, replenish it with the correct specification fluid, as noted in your Owner’s Manual
If the trans fluid appears to be normal in all respects, take the car to an independent transmission shop for diagnosis
DO NOT go to AAMCO, Lee Myles, Cottman, Mr. Transmission, or any other chain operation unless you want to be told that you need a new transmission–whether you really do or not.
At the very least, have the trans shop change the trans fluid and filter in addition to diagnosing possible internal trans problems and checking for broken motor and/or transmission mounts.

Just for future consideration–Even if the Mazda maintenance schedule doesn’t list this service, the trans fluid should be changed every 3 years or 30k miles (whichever comes first). Folks who don’t do this can usually look forward to transmission failure any time after 90k miles, and almost surely by 120k miles.

Unless you can confirm that this car has had its trans fluid changed at least twice so far, then it is overdue for this vital service. Just be sure that you don’t allow a quick oil change place to do it. An indy trans shop is your best bet.

From afar, I don’t think anyone can give you a conclusive diagnosis, but if I was in your situation, I would bite the bullet and pay the diagnostic fees a.s.a.p. Trust me…if the “noise and jerk” are a ominous as you state, this is only going to become more expensive while you delay the process.