I’m working on getting my 240 back in road shape and I tried to change the transmission fluid yesterday but the fill plug seemed impossible to remove. I ordered a 17mm square socket to hopefully not round it off and doused it in penetrating oil multiple times. Any other tips and tricks? When is searched around I read that applying heat to the transmission body around the nut can help, is a propane torch sufficient? Also, any guesses on what is causing the oil leak on the rear of the transmission and what the black oil soaked wire running to the rear of the transmission is? Thank you.

That's the speedometer cable leaking transmission fluid. Here's a thread on the seal that fixed mine and the Nissan P/N. I got mine from the local dealership they did have to overnight order it.

Edited 4 hours ago4 hr by siteunseen

To get my plug out I used a small pipe wrench and a bottle jack to loosen mine. Situated the wrench so I could get the jack under the handle then pumped the jack a few times and it loosened up.

They have a 15mm square socket available on Amazon. Works like a champ with a 1/2” pull bar. I chose the Harfington model. https://www.amazon.com/s?k=15mm+socket

Edited 1 hour ago1 hr by Yarb
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