Mercedes-Benz Ponton
Manual Transmission Fluid Change

Len Sokoloff /

Figure 1. 14 mm hex (Allen) wrench for transmission drain and filler plugs

This is an original style 14 mm hex (Allen) wrench 120 581 06 65 furnished with all Mercedes-Benz Ponton sedans, coups and cabriolets when new.

Generic, "L" shaped, 14 mm hex (Allen) wrenches are available at automotive specialty stores and tool vendors. However, in the case of this particular job, you need a wrench that has the same profile as the original tool.  The generic "L" shaped 14 mm hex wrenches will not work because of the tight space the transmission filler plug is in.

The contemporary Mercedes-Benz (Daimler AG) part number for the oil filter combination wrench is 000 589 24 07 00. As of January 2006, the tool is available through authorized Mercedes-Benz agents at a suggested retail price of $19.00.

See the Tool Kit page for more detail.

Suction gun - The filler plug, located near the top of the transmission, is in such a position that you have to pour the new fluid "uphill" in order to get it in. I bought a suction gun from NAPA for about $11.00. This neat little tool allows you to pump in a pint of transmission fluid at a time via a flexible plastic tube - uphill, downhill, sideways, whatever your pleasure. Really worked well! It is NAPA part #715-1245.

  1. The transmission fluid in the car should be warm when doing this job
  2. Jack up the car enough for you to slide under it to access the transmission — jacking up the right front worked well for me, driving onto ramps is another option
  3. Using a 14 mm hex socket, or the original Mercedes tool, remove the filler plug, to be sure you can fill the transmission after it is drained. The filler plug is located on the right side of the transmission a little ways up in the transmission tunnel. It won't do you any good to remove the drain plug and have no fluid in your transmission if you can't also remove the filler plug. The drain plug is located directly at the bottom of the transmission. Both plugs need a 14 mm hex wrench.
  4. Position your drain pan under the drain plug
  5. Remove both the filler plug and the drain plug and allow the transmission to drain — it holds about 1.4 liters
  6. Fill your suction gun with ATF and shoot a cup or so into the filler plug just to drain out any remnants of old oil
  7. Replace the washer on the drain plug and tighten It should be pretty snug [1]
  8. Fill the transmission until the ATF begins to flow out the hole — about a quart an a half
  9. Replace the filler plug and tighten it down snugly [2]
  10. Dispose of the used ATF in a responsible manner — my auto parts store allows me to mix it with used motor oil
  11. Lower the car off the jack, jack stands, or ramps before attempting to drive away


[1] [2] The torque specification for the filler and drain plugs is 14Nm (10 Ft-lbs)

Created: July 25, 1997
Last Update: September 07, 2021


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