Transmission fill & drain plug removal

[Prillco]

Time to change the tranny oil in my '72 914. Purchased a 17MM allen head socket. Following good practice attempted to remove the fill plug first (best not to drain a tranny if you can't fill it back up), but it was "frozen" and in spite of being careful the allen socket disfigured the plug hex opening. Granted I reefed on it pretty hard, but the hex opening was messed up enough I was afraid it would totally strip out and then I would be up the creek, so I put the breakover bar and cheater down.

I asked my mechanic how to remove a frozen plug and he said he uses Deep Creep and heat. YouTube videos suggested heating the area around the plug and using ice cubes to cool just the plug, creating some metal shrinkage.

Sprayed the two plugs with Deep Creep while the engine and tranny were hot from driving. I let it sit for a day. Meanwhile I noticed the 17MM socket was rounded on the "business" end, and thus didn't fully engage to the base of the plug opening. I ground down the end until flat.

Drove around to heat the engine and tranny innards, sprayed more Deep Creep, used a butane torch to heat the area around the plug, and then cooled the plug with about 3 ice cubes. The 17MM socket now made full contact, but still it was all I could do to break the fill plug loose, but it came free. The drain plug was somewhat easier to break loose, but still took a lot of force.


Don't overtighten these plugs!.

[Tobra]

Glad you had a happy ending to your story. Hope you replaced the plugs

[GregAmy]

I found a couple of plugs that were actually 17mm "outies", I needed them to safety-wire for racing. Bottom one was magnetic. I think they came from a similar-vintage 911.

[porschetub]

Everyone overtightens them why I don't know they generally seal without being gorilla tight,if you are worried clean the bungs and apply a little pipe sealant.

[Emo993]

Porschetub, you are correct. Mine stripped out, had to clean out good with brake clean and then JB Weld the socket into drain plug......next day, out it came. Best, Mark