What size wrench for differential plug on w124?
 

What do I need to remove the plug from a rear differential of a 1987 300E? It looks like a hex. I could probably make a torx work though. What size do I want before I go and randomly buy things.
Thanks
David

I have a 87 420sel, and I used 14 MM hex to for the differential plugs. Most probably it would be the same for your car also. AutoZone sell a set of 3 "1/2 inch drive hex bit set " for $8.00, get one from them. Always open the fill plug first, just in case you are not stuck with oil drained but fill plug stuck.
I hope this helps
Thanks

It's either 14 mm or 17 mm Allen hex for MB cars even though most of them have 14 mm. Do NEVER use anything else (e.g. a torx) to open these differential plugs. They are very tight and you will destroy them with your torx.

Eric

14mm hex
 

Hi
Its a 14mm hex on my 87 300d (124). One of my plugs bears the scars from a previous owner trying to open it with something stupid. If the plug is dirty get a scriber or narrow screwdriver and scrape out the gunk and crud. The hex or allen key will then fit more securely.
Gerard

TThe fill and drain plugs are 14 mm hex head (NOT Torx). They can be VERY tight. Often a 18-24" 1/2" drive breaker bar is necessary. Be sure to loosen the FILL plug first (in case you can't get the drain plug out). Its sooo very hard to turn the car upside down ;)