eric_in_sd

From my "Sudden Death" thread: I took the key out of the ignition while the car was moving, in hopes it would restart the computer. That didn't work, but what did happen was as I was slowing to a stop I heard a tiktiktiktik noise, which was the Park mechanism attempting to engage (I enabled the feature that automatically selects Park when the key is removed from the ignition). As soon as I realized what was happening, I hit the brakes, but certainly the vehicle was trying to engage the Park mechanism. It still functions normally.

Should I do any service, like flushing the transmission fluid? Are there little bits of Park pawl swirling around in the fluid?

Fourdiesel

If the car is about due (or soon will be) for a tranny fluid flush/change then do it. As long as the park pawl engages and holds correctly with the vehicle at a stop you are probably OK. If there are any 'chunks' chances are they are sitting on the bottom of the pan by now or caught in the filter.

TacSysResearch

Why in the world would MB give you an electronic shifter and not put a speed sensor on the park selector so it won't even try to engage while the wheels are turning? Sheesh.

Shifter

Um hello, he turned off the engine and even removed the key. It's the last step that automatically puts it in park. It's a safety feature so you don't get out and forget to put the car in park. Duh.

alx

Don't worry. It's the paw surfing on the gear and not being able to engage. Truck is designed to do that if you engage park while moving at low speed. If the paw catches suddenly while you are still moving- now that would be a problem.

Paul106

Just did that today on my 2016 E350 - still can't get used to the shifter on steering wheel column I meant to turn on the wipers but instead put the transmission into P while moving at ~ 5..10 mph. The ratcheting sound I heard was gut-wrenching!!! The car slowed down and halted. Everything seems to be okay after that but I am wondering if I need to do any sort of checks or transmission service. Some folks here say that there may be pieces of the parking pawl in the pan.... do I need to worry?

Thanks!
Paul.

DennisG01

Paul, read through the entire thread. The answer you seek is there.

Paul106

Yeah but the answer was about a truck! I would think they are built tougher.
I really hope someone @ Mercedes Benz thought about this when they put the P button onto the steering column :-\ and made electronic cut off speed 15 mph instead of let's say 5 It is hard to accept that a metallic sound like the one I heard is just fine.

DennisG01

The answer is about a truck because it's the truck forum. But, from your description, it sounds a lot like Eric's description. It also sounds like the advice that ALX offered applies to your vehicle. Meaning, I would think that the same advice would apply to you. Does P work normally, now?

I can't say on whether or not the parking pawl and flywheel are built differently on the GL and E. I don't enough about the differences/similarities and would only be guessing.

Paul106

Yeah, P works fine (tried a few times), thank you! I guess my fear comes from my previous experience with this 7G gearbox - I had shifting problems in both E550 and S430 (in the S430 it quit completely @ 44k miles). And I am afraid that this stress I put on my new gearbox in the E350 will shorten it's life or bring problems
Well, it seems like I can't do much about it anyways so I will just cross my fingers as usual with a MB )))

Thank you for the help!

DennisG01

I'm sure others with more extensive knowledge than me will chime in, but personally I can't imagine that causing any issues with the tranny. The tranny just knows that the flywheel was slowing down - for all it knows it was because the engine was being downshifted (at least as far as the "stress" on the tranny goes).

eric_in_sd

For what it's worth, it's the same transmission. The 4Matic / 722.9 / 7 speed is used across a wide variety of vehicles. There are minor differences, but the main portion of the tranny is the same.

It's designed to be able to do this without self destructing.

Still, the tranny shop I got my rebuilt from recommends 25K fluid changes. So if it's been a while, you might benefit from a change - including pan and filter. Apparently MB's recommendations are way too loose.