Trodas

Hi guys,

My wifes gl320 was shifting kind of hard about 3 weeks ago..than it stopped on its own and yesterday it started again...i scheduled an appointment and the rep told me it probably needs reflashed..but im thinking if it needs reflashed it would have kept doing it..and from what i see it only does it in the morning so i doubt its a flashing issue..has anyone experianced this or have any other ideas it might be..Thanks in advance.

Comfy_Couch

I've experienced the same issue - my transmission was reflashed and it's somewhat better, but it still happens when the engine is cold (i.e. in the morning). See these threads:

https://mbworld.org/forums/gl-class-x164/247208-transmission-action-downshifting.html

https://mbworld.org/forums/gl-class-x164/247173-transmission-noise.html

Some say the problem will smooth out over time.

Danno4x4

Are you sure that it is the transmission? Does it only do it when it shifts, or does it buck every once in a while randomly...

The reason I ask is that sometimes you can get water in your fuel tank which can cause bucking...Water enters fuel at refining, transport, storage, and engine operation and can sometimes just be sitting at the bottom of the tank and get sucked into the fuel pickup.

You can buy additives that will get the water out of the fuel system from truckstops....

You might mention to the dealer that this could be the case because Mercedes probably has some kind of additive that they can add into the fuel system

Trodas

my vehicle has 22k miles and it was fine up until recently,, so i saw someone said about replacing the valve body, was this a problem for this vehicle?

oknish

Valve body replacement has been a known fix for hard shifts for this transmission. Good luck getting a dealer to do that though. They will claim "unable to duplicate", "re-adaptation", and, "flashed with update" over and over and over.

Comfy_Couch

So far that has been my experience. The issue only occurs when the engine is cold, so to duplicate it, the car has to sit overnight at the dealer. But that means only the tech will be able to observe it in the morning, unless you're willing to drive back to the dealer to request to ride with him.

TRODAS, if this issue is just showing up after 22K miles, it may be something else.

BTW, is replacing the transmission valve body a big job? If so, IMO having open heart surgery at the dealer ought to be carefully weighed against the magnitude of the problem.

Nevada Jack

I don't think replacing the Valve Body is a major operation. I had it done on my '06 S430 and as I remember I picked it up the next day. This was a very common problem with the early 7G transmissions. I have not heard of it being needed for the GL at all to cure the downshift problems noted so far.