How To: Mercedes-Benz W123 Motor Mount Replacement

At Lerms Customs, we know that your car is like a member of the family. So when something goes wrong, it can be a real pain in the...motor mount. Our team is here to provide you with the best possible service to get you and your vehicle back on the road as quickly as possible.

What are motor mounts?
Your Mercedes-Benz W116, W123, or W126 has two motor mounts. They are what connect your engine to the frame of your vehicle. Over time, these mounts can wear down and may need to be replaced.

Signs that you may need new motor mounts:
There are a few things you may notice if your motor mounts need to be replaced. If you feel increased vibration when driving, or if your engine seems to be shifting when you make a turn, these could be signs that your motor mounts are wearing out. Motor mounts are essential for keeping your engine in its rightful place - under the hood (or bonnet if you're British). Mounts wear out over time due to the stress of daily driving and can cause all sorts of problems if they aren't replaced. 

When replacing motor mounts, it's important to use ones that are designed specifically for your vehicle. Many aftermarket mounts are made from lower quality materials and don't last as long as OEM mounts. We've seen many cases where people have installed aftermarket mounts only to have them fail shortly thereafter. Save yourself the headache and install OEM or Lemforder brand mounts from the get-go.

Parts Needed: 

  • (2) Motor Mounts (Lemforder or OEM Brand Only)
  • New Mounting Hardware(Optional)
  • (2) Engine Shocks w/ Hardware Kit (If Applicable)

Mounting Hardware: (2)M10x1.5x40mm (4)M8x1.25x20 Stainless Steel Socket Head Bolts w/ Lock Washers 

Engine Shock Part # 1232400948 (Same left & Right)

Engine Shock Bushing Replacement Kit # 1232400117

Motor Mount # 1232413013 (Same left & Right)

Tools Needed:

  • 6mm 3/8" Drive Allen Socket
  • 6mm Allen Key
  • 7mm Wrench(Engine Shocks)
  • 8mm 1/2 Drive Allen Socket
  • 1/2" Drive Extension
  • 3/8" Drive Extension
  • 10mm Wrench 
  • Cleaning Pick
  • Blue Thread locker
  • Engine De-greaser or Cleaner
  • Floor Jack or Bottle Jack

How to replace motor mounts:

  1. Disconnect fan shroud & throttle linkage to avoid damage when lifting the engine
  2. Use a floor jack or bottle jack to support the engine but do not lift yet. Never lift directly on the oil pan, use a piece of wood or similar to even out the load
  3. Remove motor mount bolts to frame underneath the car. The bolt is located inside the recess underneath the car. Use a 8mm 1/2" Drive allen socket
  4. If applicable remove the engine shocks using a 7mm wrench to hold the shaft from spinning & 10mm wrench to remove the nuts
  5. Lift the engine a few inches 
  6. Remove the 6mm motor mount bolts. Outer bolts are easiest accessed from the top and the inner bolts are easiest from the bottom
  7. Remove the mounts and the heat shield. Bend the heat shield back into place if it is damaged or replace it
  8. Install in reverse order

W116, W123, W126 Motor Mount Replacement Kit: