Underlook

Hi All,

2010 GLK 350.

Trying to change front differential fluid using procedure of a YouTube video. Alternator is pushed aside to access top cap.

Removed top rubber cap. Tried to put a stick down and expected to find fluid level near the top. Instead, the stick hit something solid plugging the hole. Looked at it with a mirror and with a camera inspection scope and it appears to be a tan coloured plug, with a small hole in the middle. Tried to put the stick in the small hole and again ran into something solid. The scope image appears to show a small “bar” or something across the hole under the tan plug.

I have heard that MB does not recommend changing the front differential fluid, but this seems weird.

Anyone know what is going on here and if there is a technique recommended to change the fluid?

Thanks!

This image below is using a rectangular mirror to look into the fill hole. Red arrow is the top of the front differential. Image at bottom shows the “bar” blocking the center hole, sorry for image quality.

chassis

Search this site, pretty sure it has been covered. X204 has a sedan-type 4MATIC system similar to C-Class of the same model years.

From memory I think there is no fill plug on the W204/X204 front axle and the axle is rather filled through the axle (halfshaft) hole. This requires halfshaft removal.

This video shows a non-WIS workaround:

Underlook

Yes. That will work for me.


Does not matter, but mystery is whether MB decided to make filling at the top cap not possible at some point where previously it was possible.

Filling at bottom will be much easier with the right pump equipment.

Thanks!

Mmr1

I had both changed front and rear , it was easy . On My 13 one of them you refill through the drain hole with a pump, don’t mess with sealed plugs .

TimC300

Do they usually have the fill plug on the top? I thought they were on the sides at the level they want to fluid filled to, that way it starts spilling out and you dont over fill it. The cap at the top looks like a vent/breather. Maybe Mercedes figured you will need to replace your cv axle before the fluid needs to be changed so left the fill plug out?

As others have said I used an inexpensive fluid pump and filled it through the drain plug. I already had the fill adapter for the trans. I didnt have a shut off so used some quick connects, when done pumping pull the quick connect and the fluid wont come back out while your getting the drain plug ready to put back in. Ive since picked up some inexpensive shut offs.