Can anyone share WIS for replacing motor mounts on 2010 GL450? The driver side is buried deep so I'm trying to determine which components to remove to gain access.
If anyone has done this before I'll appreciate tips and pointers. Thanks.

 

This should do:

https://www.youcanic.com/u/mercedesm...w251-w164-x164

 

Thanks, but I had seen and read that already a few times before. The details is for the R-Class. In the GL it is not the case that the "driver's side engine mount was much easier to remove because there was more open space on the driver's side." In fact, it seems quite the opposite. There is no room to fit even the MB engine mount wrench to the top of the mount and remove the 16mm top bolt so it seems like other stuff has to come out first.

Anyway, I have the WIS now an it talks about removing the complete exhaust and possibly the rack-and-pinion depending on the engine. If anyone has done this on a 2010 GL450 I'll appreciate feedback. Thanks.

 

Very few tutorials available online that are specific to this application so I will help.
1. Remove the engine bay stabilizer bar that bolts (16mm wrench) onto each strut tower. There are two 10mm bolts that need to come off on the passenger side engine firewall cage to access the bolts.
2. Remove the top engine vanity covers and the air filter intake manifold.
3. Jack the vehicle up by front right jack point
4. Underneath the vehicle, remove the two torx bolts (E12) that fasten to the passenger side (Right) engine mount from below. They are accessible with long extension.
5. Remove the two E14 bolts that bolt into the transmission mount to give extra clearance.
6. Unbolt the catalytic converter to passenger exhaust manifold bolts, there are 2 of them, they are reverse torx (E10/E11). The medial bolt is readily accessible with extensions. In order to access the lateral bolt, you will need to remove the tin heat shielding for the cat. There are 3 10mm hext bolts. A small flex head ratchet with small 10mm socker or a 10mm flex head ratcheting wrench work best. Once the heat shield is removed you will have access to the outmost (lateral) cat to manifold bolt. Then place jack under engine oil pan (with wood or rubber block) and jack the engine up about 1-2 inches.
7. From the top of the engine bay, now remove 9 nuts from the passenger side exhaust manifold. Some nuts will come off easy, and others will come off with the stud intact so use lubrication and go slowly, you don't want to damage the threads inside the head. There is an exhaust gasket at the head, you can opt to change it if it looks deteriorated.
8. With the exhaust manifold removed the engine mount top bolt is very easily accessible. 16mm wrench or 16mm specialty tool. The top aluminum cover will come off as well.
9. The mount can be removed from the bottom most easily and the new mount should be replaced from the same. The rest of the procedure is the reverse order of the start.
10. The drivers side mount is more involved. Both the exhaust manifold and the steering linkage obstructs the removal of the drivers side engine mount top bolt as well as the exhaust manifold bolts. As such my recommendation to do the drivers side engine mount top bolt is through a small window in the driver's side wheel well. There is a sheet of heat shield tin with three 10mm hex bolts that need to be removed to use the window. You will need to remove the drivers side tire, upper stab bar bolt, air strut, and disconnect the upper control arm from the spindle to create clearance so that a long ratchet with the 16mm benz specialty tool can be fed through the window and loosened. Its a lot of work, so be prepared. There is a good video of this published here: on this engine mount removal procedure .
11. The general procedure for the drivers side mount is the same as the passengers side. You may choose to drop the exhaust on the drivers side to give yourself some additional room, but I don't think its necessary. Please note that when you remove the strut you may need to loosen the control arm cam bolts, and as such you may alter the alignment. try to mark the cam bolts so that you preserve the alignment. As an alternative, you can attempt to disconnect the steering linkage and retract it out of the way of the manifold. And then you will have better access to the manifold bolts and once the manifold is removed the field is completely clear to remove the upper drivers side engine mount top bolt. However, be sure that you lock the steering wheel and mark the linkage so it lines up perfectly and you don't disturb the steering wheel alignment and center position. Good luck and best wishes.

 

I think the instructions posted by mobitechaz are you best bet, but here's the WIS docs just in case. They'll give you the torque specs for everything, if nothing else.

Edit: wow, necro thread!