Aw, tester, you corrected it!
I hope that doesn’t mean I’ll have to start correcting my many spelling/keypunching errors. I’ll be up all night every night.
Keyboard is in the shop.
Lots of coffee and cigarettes on this board.
But it still works. If you pay attention.
Tester
Gotta say, I didn’t expect such a volume and range of responses to my trivial question. Thanks for all the varied replies, opinions, and minor disagreements. Goes to show no procedure is too mundane to have five different people do it five different ways.
Next topic: best way to tie shoe laces… 
Well my wife claims that I don’t know how to tie my shoes. I’ve been doin it that way for 60 years but she says its wrong. I will have to admit they do come loose once in a while. I think its best to avoid the whole issue and use slip ons.
Bing, its probably because you didn’t use crushable Loc-Tite on your shoe laces…
I wish I could still reach my feet…
@SameMountainBike
Guess this hit home a little for me when just recently, as I mentioned, the DEALER failed to replace the washer in the transmission plug during service and a friend who was using the car noticed the leak. Without this happening, I could have faced transmission failure in a car I had festidiously maintained for ten years.
My son and I have been using and re-using nylon washers for well over 200,000 miles, each. I have had no problems with re-using the nylon washers, though we do inspect them carefully each time. At any sign of damage a new one goes on.
And, my car goes around 8,000 miles between changes. Mobil-1 Extended Performance, this decision was made after having my oil tested by Blackstone. Not in the snow zone, and mostly highway driving.
I do not recall ever seeing a crush able washer in any of my vehicles starting with a 61 olds,for a drain plug, is that an extra?
Nope. Some cars come with them, some don’t. There’s more than one way to seal the hole.
Personally, I’ve changed oil on cars that didn’t use crush washers, but they always had a washer of some type, usually made of copper, and they never sealed as well as I would have hoped. However, if you go to a Honda dealership parts department and ask for an oil filter for a 6th Generation Civic, they will include an aluminum crush washer whether you ask for it or not, and I really appreciate that. I don’t buy oil filters at dealerships often, but when I do, and they take that extra step, it makes me feel better about letting them change my oil to know they consider a fresh crush washer a necessary part for the job.
I have never owned a car with a crush washer. Most of the Chrysler products I have owned in the last 30 years have what looks like an O ring built into the drain plug but it is fairly hard and not removable.
The only time I have ever had to replace a drain plug is if I have been foolish enough to let someone else change my oil. (Usually on a long road trip) and they always put it back in incredibly tight and it looks like the only tool they use is a vise grip.
I haven’t personally run across one that uses an O ring as previously mentioned, but I have no doubt they exist.
My 1989 Dodge B250 has that O-ring oldtimer mentioned. It seems to work well.
All Benzes use copper drain plug washers
I always replaced the washers, and I never had a drain plug leak past the washer, or fall out at a later date
Mind you, I’m only talking about Benzes, not any other brand that also uses a copper drain plug washer
I will add something, though . . . I’ve seen guys reuse the copper drain plug washers, and it’s a wash. Some of them sealed fine, whereas others leaked past the washer, because it was already deformed from the previous use
Hmmm, I just bought 5 quarts of Acura trans fluid for $50 and had to ask for the washer. Another $2.34. Seems to me they could have thrown it in. Now just have to wait till it warms up a little.
Absolute sealing is not quite as important to me as holding power. IMO, the combination of a really deep thread, a good off metal washer that deforms slightly gives me the most confidence. The more thread the better both leakage and holding power. On some machinery, loosing a drain p,ug just doesn’t happen because of this. Just wondering but, could something be done with a magnetic plug to help it resist turning ?
The best resistance to turning is from friction created by torquing the plug properly in the first place.
I must be the luckiest person alive- in 45 years give or take, I have never once replaced the sealing mechanism for a drain plug on any engine I have owned. None have ever leaked a drop let alone fell out unexpectedly. Crush washers, copper flat washers, nylon flat washers and o-rings…seen them all. Then again, I never let anyone else service my stuff and I simply use a small ratchet gripped at the head to apply the final sealing force.
@TwinTurbo, I find that claim dubious, that no drain plug you have ever used has ever let loose a drop of oil. If a drop of oil did fall to the ground from your drain plug on a really cold day before your engine warmed up, you’d never know.