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I just finished the procedure:
Seeing one bolt new and the other old is normal.
When you go to buy the crush washers, they won't sell you the crush washer of the drainplug, but the assembly of the bolt with captive crush washer.
So, if you do this right, there always will be a brand new drainplug.

Meanwhile, for the fill plug, the copper crush washer is also captive, so I had to cut it off with a bolt cutter and then the new one went in without problem.

The part number of the oil is different than the one seen in the video, per WIS.
However, nobody will sell that and they can't order it, because it's hazmat.
So, the parts guy at the dealership told me that the last two digits of the part number of genuine fluids indicate the quantity and sold me a container with the same part number as the one in the video.

The torque for both plugs is 15Nm.

Mine was low by like half inch, the oil looked not that bad. But gear oil doesn't necessarily get dark with the mileage.

Turning the rear wheels, I had to try several things to get to have the engine off, transmission in neutral and parking brake off.

I started to look at Xentry. I did not at all indicate that you should drive the car while actuating the valve. It indicated that a crewman turns the rear wheels with the engine off and ignition on, while the technician operates the valve and they both try to identify a jolt and recheck the level. The jolt should indicate that the procedure is complete and the level is sufficient.
I actuated it a few times and turned the wheels, no dice.
I tried to see what happens if I try to drive it.
If you drive it, Xentry suspends the availability of the valve actuation.
Except if you're in neutral.
So I tried to parking lot drive it at low speed, then let it roll in neutral and actuate the valve.
I actuated it 10 times, no dice.
Went back, was able to add a small amount of oil.
Went through the whole driving thing again, still no good, except when i rolled into my driveway and actuated it while turning in neutral. Then I definitely felt a jolt.
Put it back up, as soon as I pulled the fill plug, it started to weep oil. So it was good now.

Shot some video, I'm lazy with the editing.
Made a mess in the driveway...
 

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Thanks for the info on that, I appreciate you taking the time to explain it. It sounds like you really need Xentry to get the valve activation and the correct level; is that correct? For those of us that don't have Xentry, do you happen to know when that valve may activate during normal driving? What I am getting at is this; if I change my diff fluid and drive around for a day or two, would that valve activate during that time and then would I be able to check the level and add as required?
 

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I’m not sure yet.
I know that what is commonly known in other cars as electronic center differential, is a unit that is located on the rear differential with this car.
the unit is not a stand alone smart unit but something that is directly controlled by the ECU, or TCU.
It could be something as simple as a hydraulic valve, maybe that operates on pulsations, and depending on how many the ECU sends, the center differential sends more or less torque to the rear diff.
If this were the case, the unit would be working most of the time, especially when you’re out of the comfort driving mode.

One way in an AWD car with a trick center differential, to know whether the AWD is engaged or not, is to make tight turns in parking lots. If the car is binding, AWD is engaged.
I know mine has been binding, but didn’t think yet to toggle between S and C in the parking lot to see if the binding goes from one extreme to another.
this right here may be the answer and the valve actuation. I will try it today and so should you.
 

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Mercedes GLA 45 AMG
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I just finished the procedure:
Seeing one bolt new and the other old is normal.
When you go to buy the crush washers, they won't sell you the crush washer of the drainplug, but the assembly of the bolt with captive crush washer.
So, if you do this right, there always will be a brand new drainplug.

Meanwhile, for the fill plug, the copper crush washer is also captive, so I had to cut it off with a bolt cutter and then the new one went in without problem.

The part number of the oil is different than the one seen in the video, per WIS.
However, nobody will sell that and they can't order it, because it's hazmat.
So, the parts guy at the dealership told me that the last two digits of the part number of genuine fluids indicate the quantity and sold me a container with the same part number as the one in the video.

The torque for both plugs is 15Nm.

Mine was low by like half inch, the oil looked not that bad. But gear oil doesn't necessarily get dark with the mileage.

Turning the rear wheels, I had to try several things to get to have the engine off, transmission in neutral and parking brake off.

I started to look at Xentry. I did not at all indicate that you should drive the car while actuating the valve. It indicated that a crewman turns the rear wheels with the engine off and ignition on, while the technician operates the valve and they both try to identify a jolt and recheck the level. The jolt should indicate that the procedure is complete and the level is sufficient.
I actuated it a few times and turned the wheels, no dice.
I tried to see what happens if I try to drive it.
If you drive it, Xentry suspends the availability of the valve actuation.
Except if you're in neutral.
So I tried to parking lot drive it at low speed, then let it roll in neutral and actuate the valve.
I actuated it 10 times, no dice.
Went back, was able to add a small amount of oil.
Went through the whole driving thing again, still no good, except when i rolled into my driveway and actuated it while turning in neutral. Then I definitely felt a jolt.
Put it back up, as soon as I pulled the fill plug, it started to weep oil. So it was good now.

Shot some video, I'm lazy with the editing.
Made a mess in the driveway...
 

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Mercedes GLA 45 AMG
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2 Posts
Hello everyone, i know it's an old thread but maybe my post will help.... I just made the changing of oil in the rear differential from my GLA 45 AMG, and i want to give two precisions :
1) You need to turn the back wheels by hand together in the same direction after having taking off the bleed screw and let the oil go out. This is needed to "force" the oil staying in the rear diff to go out.
2) When you use Xentry to activate the solenoid valve, you can do it while running the car with a gear engaged (not in N position). You turn on a large place with your car, keeping the steering wheel fully turned, then you press the > in Xentry to activate the solenoid and you should feel a jerk (i can tell you, it's really felt).
Sorry for my bad english, i'm a french guy......
 
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