So I posted a few weeks back about a clicking sound my 07 base TL was making. Since then I've replaced the Front and Side motor mount and will be replacing the upper transmission mount soon. I also replaced the two 4th gear pressure sensors and hope to replace the 3rd gear next week. I checked and there are no codes present.

The car was previously making a single "click" that could only be heard from the driver side when I reversed from a stop or when I manually down shifted and let the engine "brake". After replacing the motor mounts (both of which were completely shot) the single click turned into 3 quick clicks in succession. It also started to exhibit this sound when starting from a stop and accelerating somewhat quickly (not flooring it). It still clicks when you down shift and allow the engine to brake but also will now click if you accelerate in gear and then allow the engine to brake.

It seems to only make this sound when momentum is changing. It will make it initially when accelerating for example, but will not make the sound again until I shift the momentum in the opposite direction (such as downshifting and allowing the engine to brake, thus shifting momentum in the opposite direction). Accelerating through the gears does not cause any additional "clicks".

The transmission seems to be operating normally and don't notice any slippage, flaring or otherwise abnormal behavior. I'm wondering if this click could be due to some joint or axle. It doesn't make it when just driving in a docile manner, or under any corning. It also doesn't manifest itself in "D" mode except for the initial acceleration from a stop. My supposition here is the car stays in such a low RPM band in D, when it down shifts there is no momentum shift to speak of in the drive train.

Any thoughts on my next course of troubleshooting would be very welcome Thanks!

 

Sounds like CV axle to me..