[Issanesh98]

Hi all,

My brother has a 2010 glk350 with 150k miles purchased privately around a year ago. It started having shudders and power loss after 1st gear. There was no check engine light or anything but I figured it was a transmission issue so I told him to take it to the tranny shop. They quoted him $1800 for a new torque converter. Their idea is that the lock up clutch is failing. Before emptying our wallets, I decided to try and change the fluid myself and see if the issue would go away. I changed about 6L of fluid and we noticed that the car regained power and the shudders are 80% cleared, but still there. While slowly accelerating, I notice the rpms shifting up and down like a manual transmission clutch slipping and catching. I think the new fluid is allowing more slippage so its not as rough. I fear that the car might need its torque converter replaced, but I wanted to ask if it was worth dropping the valve body and conductor plate to replace the torque converter lock up clutch solenoid. This would cost around $250 to change out properly. I have no doubt in my ability to do this project, I just want to ask if it is worth it, or to have the shop take the transmission out and replace the whole converter. Thanks in advance for your advice and thoughts

 

[Issanesh98]

To add to the story, the old fluid didnt have any shiny particles or chunks. It just looked dirty from not being changed. I also didnt drop the pan since I didnt have a spare gasket, new bolts or a filter on hand. I simply drained the torque converter and refilled through the pan

 

[John350]

If changing 6 liters of fluid helped, I'd do a full change with filter and see if that helps more. Do you know the service history? Even if it was changed once, at 150K it's almost due again.

 

[Issanesh98]

No idea for the service history. My guess is it was never changed. If I change the filter and fluid again, I might as well change that solenoid too. Its only $50 from FCP euro

 

[John350]

Can't hurt...

 

[Revrdmark]

I purchased a used 2013 GLK350 4-matic a year ago and had the same issue a shudder at shifting in lower gears. I took it to a Mercedes specialist locally and he said that it may be the torque converter (just as you thought with yours) Because of the design of the 4-matic transmission that was an expensive proposition ( was told considerably more than $1800 you were quoted... it was almost a year ago so i forget what specifically added costs to this model) He recommended doing a full transmission flush with new fluid to see if that had any results. He did the flush and within 2 days the shudder was gone. I drove my wife crazy driving it accelerating at different speeds to try and make it come back just to see if it was really gone. I had the flush done about 10 months ago and it hasn't returned. I on occasion pull a small motorcycle trailer behind my GLK350 and even with the added weight it hasn't returned

 

[Issanesh98]

Good news! My brother is saying the issue has gotten better each day of driving it. He says he cant feel it anymore and that the rpm gauge isnt fluctuating. When I get back home, Ill just do that fluid change and call it a day. Thanks for the input

 

[MikeC123321]

Good news! My brother is saying the issue has gotten better each day of driving it. He says he cant feel it anymore and that the rpm gauge isnt fluctuating. When I get back home, Ill just do that fluid change and call it a day. Thanks for the input

Can you post the process ? I am looking to get this done, I have the same shuddering

 

[Issanesh98]

Hi MikeC123321,
I simply drained the torque converter and the pan and replaced the fluid as per the refill process. There are plenty of videos on youtube showing how to do this and what tools you need. I didnt drop the pan since I didnt have the parts at the time but if you plan to change the fluid, I would recommend changing the filter, gasket and pan bolts as well.

 

[MikeC123321]

Hi MikeC123321,
I simply drained the torque converter and the pan and replaced the fluid as per the refill process. There are plenty of videos on youtube showing how to do this and what tools you need. I didnt drop the pan since I didnt have the parts at the time but if you plan to change the fluid, I would recommend changing the filter, gasket and pan bolts as well.

Thank you,

I actually didn't have the tools, so I had an indy shop do it locally,

thank you

 

[RussBarnes]

Had my '15 GLK350 in because It had reached 55k and the B2 due in so many days showed up. Since it's a new-to-me car and I had done all but the trans flush and filter I bit the bullet and went to the dealer. I too had a shutter while accelerating cold. M/B dealer looked everything over and decided that I needed new motor mounts. Hum, I can't help but wonder if they thought they would get a piece of that pie?

 

[MikeC123321]

Had my '15 GLK350 in because It had reached 55k and the B2 due in so many days showed up. Since it's a new-to-me car and I had done all but the trans flush and filter I bit the bullet and went to the dealer. I too had a shutter while accelerating cold. M/B dealer looked everything over and decided that I needed new motor mounts. Hum, I can't help but wonder if they thought they would get a piece of that pie?

There is a way to test if it was the motor mounts,

step on the brake, and rev your engine, if you see it move up and down to a certain degree, then yes, it might also be the motor mounts, but if you get the shudder, it might as well be the transmission flush that you will require, and check around, the Indy shops which specializes in importsare actually very helpful.

 

[RussBarnes]

Thank you for your support . I have driven it a little since the dealer transmission flush and with each step ot gets a little better. I'll try the motor mount next week when I'm home. I also tried the non running, position 2, hold the gas pedal wot for 30 seconds, and again "slightly" better.

 

[John350]

I also tried the non running, position 2, hold the gas pedal wot for 30 seconds, and again "slightly" better.

Is this to cause the transmission adaptive learn reset? If so, for my 2014, at least, the process is a little more complicated:

1. Turn the key to position II (run). Do not start the engine.
2. Press the throttle to the floor. Activate the kickdown switch. Hold to step 5.
3. Keep the gas pedal pressed for at least 10 seconds.
4. Turn key to OFF, position 0. Don’t remove the key.
5. Release the gas pedal.
6. Wait 2 minutes. During this process, key is left in the ignition in the OFF position.
7. Start the car and drive for 15 minutes.

 

[RussBarnes]

Yes, since mine is a '15, I found this tip on another search and figured it couldn't hurt. The post I read had a video and showed 30sec, so that was what I used. I have a '67 Olds Toronado that used a "Switch Pitch Torque Converter" and it acts about like my GLK does when you push all the way down on the gas pedal and feel the engagement of a switch and it leaps ahead. The Olds were infamous for the vanes in the converter getting sticky if they weren't used. That made me think if this car had the same feature that unsticking them might work. And, like I mentioned , it did seem to help a little. My "shutter" is just during the warm up phase and is totally gone after a mile or so, which is why I am skeptical that it's the mounts.

 

[John350]

I have a '67 Olds Toronado that used a "Switch Pitch Torque Converter"

OMG! Now I'll never be able to "unremember" that! However, I doubt there's anything common between that TH400 and this 7G-tronic.

The process above will cause the transmission to re-learn all the adaptation information.

 

[RussBarnes]

Latest: just changed all spark plugs. Shutter still there, only when first driven a mile or so. So it's had tranny oil and filter service, new air filter, new spark plugs, looked at engine revved with brake on (fine) and transmission reset.....it's better that when I picked it up, but still there.

 

[MikeC123321]

Latest: just changed all spark plugs. Shutter still there, only when first driven a mile or so. So it's had tranny oil and filter service, new air filter, new spark plugs, looked at engine revved with brake on (fine) and transmission reset.....it's better that when I picked it up, but still there.

Can you see if you can do a full transmission flush ?

 

[RussBarnes]

MB dealer did a full flush, new filter and approved fluid.....at least that's what I paid $7xx for. This "shutter" may be normal for these, it goes away in a mile or two, just something that I'm not used to and would like to smooth out.

 

[MikeC123321]

ok just making sure, I had a similar shudder and went to indy shop and got it rectified