diff drain plug size on 83 240D ?
 

Anyone know the size of the diff drain plug on my 83 240D? It looks like 14 MM ,not sure. Also it has 223000 miles on it dont think it was ever changed by previous owner I would like to go synthetic, any recomendations? thanks.

Should be 14 mm hex which you can get at AutoZone. The plugs are usually very tight, especially after 200kmi.

There are quite a few good synthetic gear oils you can get. Most are of the 75W-90 viscosity. Mobile 1, Red Line, etc.

I have used Mobile 1 75W-90 and Redline 75W-90 and 85W-140 and they are all good.

thanks
 

I will spray the plugs with penetrating oil. Thanks for the reply.

Make sure that you loosen or undo the fill plug before you lossen the drain plug. I've heard of people draining the diff. without being able to re-fill.

240Diesel,

The drain plug is 14mm, and they never should be loose enough for you to twist it off by hand, as I believe it is a tapered thread, like a pipe thread. I get mine off by tapping with a mallet or hammer to get it to move the first quarter turn or half turn, after which it can be turned with reasonable force by hand. When I put them back in, I turn them as tight as I can by hand, then snug it up with a couple light taps of the hammer/mallet to get part of a turn, like a flat or so. It is a feel thing, and you do not need to smash the plug into the hole, but you do need to get it tight enough to stay.

As was already pointed out, make sure the fill plug comes out before you remove the drain plug. I use the RedLine products (www.redlineoil.com, I believe) and after as much as 60,000 miles it comes out pretty clean. I usually change it in under 40,000 miles, but once I got distracted and forgot for 60,000 and there were no ill effects (that have shown up in the next 120,000 miles).

Good Luck, Jim

Praise be to this forum!

Before I did my diff oil change, I happened to run across this very piece of advise, and I am glad I did.

I would not have thought of it otherwise. :rolleyes: