C300 tranny and steering knocking sound
 

I sometimes get a knocking sound when turing to steering wheel full left or right when i am driving off the parking lot (hot and cold start). Also, i am getting some hard shifts with the tranny when i am trying to stop from a red light. the "knock" of the shift seems to happen in "C" mode and when down shifting from 3rd to 2nd. Anyone getting the same problem and knows a fix? thanks!

Yep, i made a post about it while ago.... no one seemed to have a solution... i also brought it to 3 dealers, and 2 foreman test drives.... the answer........ THATS HOW THE CAR WAS BUILT......

My tranny some times bucks lightly when I pull up to my driveway. Basically I pull up to my driveway, then wait till my garage door is up. Lightly touch the gas and it sometimes feels like it's not in the right gear for a moment. Every now and then it will do the same after stopping at a light or stop sign and turning right. I have not yet addressed it with my dealer, but thinking of changing the tranny fluid with some Royal Purple or AmsOil in the near future and see if that fixes it? I had a W204 rental while our car was in for other repairs and It didn't do it so I know it's not just me.

-Ryan

I haven't observed that thing with the tranny, then again I also drive 100% in "S" mode. As far as the knocking, I notice that too. I hear it only when backing up, and of course when turning the wheel. I don't hear it at any other time during the drive, which is why I haven't given it much attention.

I do plan to bring it up with the dealer eventually. I am inclined to wait just before the warranty expires before I do to increase the chance that a TSB would be out, a "fixed" replacement part becomes available (in case of an error in design), and to maximize the out-of-warranty time with the new part.

Regards,
Paolo

Bucking is apparently one of the features of the 7-sp tranny. Try this: stop at a red light, the hit the gas because the light goes green as soon as the car actually stops. She'll buck. It's not settled into whatever gear it thinks it needs yet. My suspicion is that when you stop it takes a wee bit of time to hit first, but if you hit the gas while it's trying to find first, it'll buck.

If you can't find a cooperative red light, try doing this in a vacant parking lot.

yess i get the same sound when turning the wheel all the way to the right of left. i have a 6 speed so i cant comment

What's even more interesting (in my case at least) is that the knocking ONLY comes out when the car is going in reverse. No matter how I aggressive I turn the wheel, as long as i'm moving forward, the knocking sounds are absent.

Maybe it isn't in the steering column like we think?

Regards,
Paolo

Mine does it ONLY in reverse too. It just started doing it at 4500 miles. Knocking sounds when approaching full lock. But the power steering has always been noisy in the car...as a matter of fact, the steering seems to be noisy is my moms E350 and my dads ML350 as well.

Has anyone taken their car in for this?

mine has the grinding feel only in reverse and turning right. I plan on adding that to the list on my initial visit and will post what they say if someone doesnt beat me to it.

You just described our trans in our C300 sport to a T. Like I said doesn't do it all the time but certainly way more than I would expect from this type of car.

-Ryan

stickshift :) no problems

+1:y...of course we all have the same steering and mine is doing the same thing:confused:

wow honestly is this something to even be complaining about?? Oh no you felt the car shift and it wasn't smooth enough?!?!?! that's how the car was built, if u didn't like it then u shouldn't have gotten it.

The bucking is caused by catching out the torque converter lock up clutches. Improved with later software.

so they fixed it?

and also, you can always use the shift pedals or manual mode to put it in first at a stop light :P, until they fix it...

I think it's fair to say improved the chances of you catching it out. You can still catch it out if if you brake hard and the hammer the throttle without coming to a full stop. This problem goes right back to the 722.6 5 speed auto. Drive smoothly & it's unlikely you will catch the box in lock up transition.

Remember for efficiency these boxes never free wheel - The torque converter is locked from just after pull away to just before coming to a halt.