Hi, all.
I was responding to a question about auto trannny fluid level a few messages down, when I remembered that I always wanted to bring up a little "fact" that I discovered accidentally, to see if anyone else also discovered, or has heard of, this.
On the several 240's I've had, at least from 1980 through 1993 (and maybe even earlier ones, but I can't remember "when" I came to realize this), I've found that when I have the ATF level correct (based on a warmed up transmission and the proper dipstick scale for the temperature), I've confirmed that there is also a way to reliably (at least, consistently) confirm proper fluid level when the engine is stone cold and not running....e.g., after you've let the car sit overnight.
On the dipstick, above the plastic part (that has the two temperature-specific scales), there is a little rectangular notch on the metal portion. Assuming the fluid level is correct, and the car is stone cold and you haven't started the engine yet, if you withdraw the dipstick and wipe it off and then reinsert it, then upon withdrawing it for this second time the fluid level should be on that notch.
[this does NOT work if you just withdraw the dipstick and look at it -- you MUST withdraw it, wipe it off, and then reinsert it before withdrawing again to read the level. I don't know why you need to withdraw it twice, but it works.]
Has anyone else ever discovered this?
I'd love for others to try this out and see if you find the same thing (the ATF level must be correct in the first place, of course).
Let me know if you find the same thing.
Thanks.

Ken -
I think what you found out is great. It was always a pain in the ass and the accurracy was just not there when having to measure the level when the engne was hot and the car was running. The dipstick never had a clearly dry section and a wet section; no matter how many times I tried.
Maybe I can give somethng back to you. You may already know and use this "trick". It involves an easy way of getting the xmission fluid into the pipe. I simply pull the dipstick out, take a rag and nudge it between the pipe and the clip to keep the clip away from the pipes' opening. Then I put the dipstick into the pipe only about 3 or 4". I take a penlight and set it down on something and point it towards the pipes' opening so I can see what's going on. Then I take the quart of xmission fluid and SLOWLY pour it onto the top of the steel portion of the dipstick. It will adhere to the steel and run down the dipstick into the pipe. You can bend or angle the dipstick quite a bit. But if it is bent too much, the fluid will "jump off" the dipstick (it will lose its' surface tension). It doesn't take long to empty a quart this way.
- Matt
--
Matt

Thanks about the ATF pouring method. Actually, I've done this routinely in my lab with a glass rod to pour chemicals into a flask when a funnel wasn't handy -- but like in lab, I prefer a funnel when pouring anything into my car. I've got a big one (about 2 qt capacity) yet with a very narrow tapered neck that fits tightly into the dipstick tube -- it's perfect, standing on its own so it won't tip. And I got it at a PepBoys store! You might want to take a look there.
Thanks again.

The reason you have to remove the dipstick once and reinsert to get good readings is that the dipstick has an O-ring at the top. It seals to the tube, making an air space at the top. The fluid doesn't flow up the tube with this air bubble trapped at the top. By pulling the stick, you break that seal and the tube then fills to the level of the sump. This applies to the normal "running" method of reading fluid level as well.

Thanks for the level indicator info!
--
Rob Bareiss, New London CT ::: '87 244DL/M47- 220K, 87 244DL- 230K, 88 744GLE- 198K, 91 244 180K, 88 244GL 145K

That makes sense about the O-ring -- I figured it was something like that. Thanks.
But have you also found that your proper level falls on that notch, too? I'm hoping that I can get some corroboration!
Thanks.

I'll try it, I've got a few examples hanging around! :)
--
Rob Bareiss, New London CT ::: '87 244DL/M47- 220K, 87 244DL- 230K, 88 744GLE- 198K, 91 244 180K, 88 244GL 145K

Also, as the tranny cools, that trapped bubble of air cools and contracts. The contracting gas will pull the liquid up the tube, giving a false reading.

Boyle's Law (PV=nRT).

Foster's Law: A cold one is better than a warm one.
--
Don Foster (near Cape Cod, MA)

That Law may only hold in the Western hemisphere.

Hmmm. Methinks you're right.

How about the first corollary: "A cold one is better than none at all."

Or...

"A cold one will become warm if you give it a chance."
--
Don Foster (near Cape Cod, MA)