how do you check the rear differental oil?

[JDmills]

I have not got a allen head or hex key wrench big enough to check the differental oil level, any one have a creative way to get that plug off, and if not what size wrench fits?

Thanks,
jason

[tangofox007]

14 mm. Recommend the 1/2 inch socket type allen. Those plugs are frequently tight. Autozone sells a set of three sockets which includes the 14 mm. Not the best quality but the price is only around $9. They will suffice for occasional use.

[JDmills]

Thank you, I will go searching this morning for one.

[Hatterasguy]

Make sure to take the top plug out first! If the bottom one comes out and the top one is stuck, well you are to!

[JDmills]

I am just looking to add oil at the moment, not interesteed in draining anything in this weather!! that will come this spring, Thanks for the warning.

[leathermang]

I posted pictures of my easy ratchet high but controlled force applying set up... should come up on an advanced search.

[deeph8]

I changed the diff oil on my 1983 300d this morning. I planned it for weeks in advance and assumed the plugs would be a bear to open. So I shot the plugs with p-blaster each night for about 2 weeks. I don't know if this is why, but they opened with minimal force. I learned my lesson several years ago when changing the transmission oil on my 535i. That time it took a breaker bar with several feet of pipe to break them free.

[leathermang]

You can't tell until you try..... if you are the first person in a 20 year old car's life to try to take it off... it may well be tight.

[Lycoming-8]

I have found that the strange dog-leg wrench in the original tool kit with either the 190Db or the 220D/8 fits these plugs on the 123. It has a 14mm hex stub on both ends and works quite well for this application. Haven't needed to use anything else on the '85 parts car or the '83 driver, but the '85 had been opened up at least once before. Does any one know when this tool was no longer included in the tool kit?