This is more of an advice post based on my experience. The first abs/rpm/wheel speed sensor failed on my 2008 GL450 at 116k, miles. About a 1k miles later, a 2nd one failed. I should've known better, but left the other two originals in place. After I hit 120k miles, a 3rd one failed. Unlike the others, this one caused the transmission to do some wacky stuff like not upshift past 4th gear and even throw itself into neutral. Luckily I was able to easily pull over, clear the trans trouble code and drive home normally (albeit ABS and ESP dash lights on). This time I will preemptively replace the last original one on my GL.

All this was to recommend to others...save yourself the headache and replace all of them once one fails if you have a higher mileage GL. It's really easy to do, which is nice

 

Yeeaaah with regard to your transmission issue I don’t think these are the speed sensors you’re looking for.

that would be the vehicle speed sensor on the valve body in the transmission. Known issue.

failing wheel speed sensors (easy fix) are always changed in axle pairs and if not; result in ABS, ESP, diff overheats and sometimes variable speed steering errors. I’ve never heard of these triggering transmission errors such as locked in gears or neutral pops.

 

Thanks for sharing. Wonder where did you buy the speed sensors, from a MB dealership? Thanks again.