Changing the transmission fluid (once more)

[DrWin]

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So this happened today while I was refilling the transmission: The dipstick broke.
That's pretty annoying, but easy to remedy. I ordered a new pan gasket and a new dipstick from Ed.

But that only scratches the surface of the many questions I have about the mysteries of the automatic transmission (fluid):
I spent last night crusing the internet for answers and found all sorts of answers. (?)

I read that I need to add 2.5L transmission fluid when doing the change, I also read 4.5L, I also read 4.5 quarts (4.1L). When reading about the automatic transmision I read that a full (assume US) gallon (3.8L) stays in the final drive, why I'd suspect I'd need to put 2.2L back in, as the total capacity is 6 L. I'm confused.

I also read in the manual that it takes ATF Dextron II, which I've been using, but internet ressources says ATF Dextron III. Which is it, and why?

I was pointed to the Renault 4141 manual for the transmission and read about a temp probe that should go into the transmission to measure the temp, so it gets tested at the right temperature instead of "after a few minutes of idling". I can't find a place that sells the mentioned temp. probe.

Also - and perhaps most basic and important - why the hell am I having such a hard time reading the dipstick? I think it's very difficult to get consistent readings when checking the automatic transmission fluid level. Am I the only one having this problem? To me it looks like the dipstick will come out with light coating no matter the fluid level and when I put fluid into the transmission I get very inconsistent readings from test to test. Is the dipstick orientation specific? Where should the fluid stand "after a few minutes of idling"?

So many questions, so little understanding. If anyone would help me wrap my head around this, while I wait for my package from Ed, I'd sure appreciate it. (Also I have a sneaking suspicion that my transmission would appreciate I got some help.)

1. How did the magnet in the pan break?
2. How did the dipstick break?
3. Where do I get a renault temp guage for the transmission fluid?
4. What is the actual deal with the dipstick, why is it so hard to read?
5. Should I change from ATF II to ATF III?
6. If so, will that make the dipstick easier to read?

[Michael]

Final drive takes gear oil, not ATF. The reason you don't replace the full amount is the fluid in the cooler lines and converter stays in place as well as say 1/4 qt in all the tight spots and passages.

The neodymium magnet is very brittle, you can't drop it in the pan. If it smacks a surface hard, it will break.

I don't know anything about a temp probe, but you have to check the fluid at a proper time. Fluid has to be at least warm. Engine running, car in park, level ground. New fluid is hard to see but if you have just added fluid through the dipstick tube, you can't immediately check the level as all that fluid in the tube has to work it's way into the pan and settle.

Manual is outdated. Just get Dextron III and be done with that. I'm not even sure if Dextron III is avaliable anymore...seems like the last time I checked another "one size fits all" fluid was on the shelf, Dextron VI? IDK, but just tell the 17yr associate that's never changed a oil filter that you are working on a DeLorean Renault 4141 and he will be sure to help you out.

[DrWin]

Manual is outdated. Just get Dextron III and be done with that. I'm not even sure if Dextron III is avaliable anymore...seems like the last time I checked another "one size fits all" fluid was on the shelf, Dextron VI? IDK, but just tell the 17yr associate that's never changed a oil filter that you are working on a DeLorean Renault 4141 and he will be sure to help you out.

Yeah...

[DrWin]

Final drive takes gear oil, not ATF. The reason you don't replace the full amount is the fluid in the cooler lines and converter stays in place as well as say 1/4 qt in all the tight spots and passages.

Right, got it. I wrote that wrong. I have gear oil in the final drive, not ATF.

The neodymium magnet is very brittle, you can't drop it in the pan. If it smacks a surface hard, it will break.

Roger, that is propably what happened, I checked that I couldn't hit it with the dipstick, so it isn't that either.

I don't know anything about a temp probe, but you have to check the fluid at a proper time. Fluid has to be at least warm. Engine running, car in park, level ground. New fluid is hard to see but if you have just added fluid through the dipstick tube, you can't immediately check the level as all that fluid in the tube has to work it's way into the pan and settle.

This! This is my problem. How warm? How long to settle?

Manual is outdated. Just get Dextron III and be done with that. I'm not even sure if Dextron III is avaliable anymore...seems like the last time I checked another "one size fits all" fluid was on the shelf, Dextron VI?

Roger. I'll look for some Dextron III when I get my spare parts.

Thanks again for the input.
You have an automatic -would you mind sharing how you do this refilling the transmission oil manouvre?

[Michael]

If you drain 2.5qts out, put 2.5 back in. The "cold" portion of the dipstick gets you close. Start it up and let the fluid come up to temp and check the level. After a short drive just to make sure the fluid is hot, I always check it again. It takes a few minutes for all the fluid to leave the tube so just clean the garage up while you wait.

It's not a bad idea to check your fluid level after a drive every so often, once a month, few times a year depending on how many miles you drive. Also keep a watch on the final drive level. Many leak into the trans and as a result, many final drives are very low.

[David T]

It is impossible to drain all of the fluid out unless you take it all apart. Much of it stays in the torque converter. All Dexron is backwards compatible, you probably won't find II anywhere anyway. It can be difficult to read the dipstick especially if it is overfilled. Follow the procedure in the manual. Don't forget the final drive must be checked separately and uses a different fluid. You cannot take the Renault manual directly and use it for the Delorean. Forget about the temp probe. Do not put back the same amount of fluid you took out, it may have been overfilled. Fill to mid-way between the add and full marks when hot on level ground. If you took the pan off you should either clean the old filter or replace it. Because you can't get all of the old fluid out you *could* go to a service station that has a power flush and have them flush the transmission. They hook up a machine that flushes the old fluid out and fills the transmission with fresh fluid. Best you can do without taking the transmission out and apart. Not really necessary unless your old fluid is very dark and burnt.

[Michael]

Blah blah blah...repeating previous postsverbatim...blah blah blah.....Because you can't get all of the old fluid out you *could* go to a service station that has a power flush and have them flush the transmission. They hook up a machine that flushes the old fluid out and fills the transmission with fresh fluid. Best you can do without taking the transmission out and apart. Not really necessary unless your old fluid is very dark and burnt.

Do NOT ever take your DeLorean for a "power flush". This is a BS service designed to make money off of soccer moms and Gurus. It could seriously damage your transmission and best case do more harm than good. It's utterly ridiculous to even mention doing this.

If you are determined to change all your fluid, my solution (and one that I have been following for the past 3 or 4 years), just drain your fluid every other oil change. The plug is right there, it's no problem to drain and refill without dropping the pan(still do a full service every 12k miles however).

Guru disagrees with me when I said to replace what you drained out because it may have been overfilled OK...ASSUMING you have been driving around since the last service not overfilled, you will be OK. If Guru's logic holds, you MUST do a full service every 3k miles because it's possible the trans was last filled with Cheerwine. Also replace your filter because someone may have used a dish sponge instead of a OE filter and as long as we are pointing out long shot scenarios, be sure to clean out all the dead birds from the transmission pan that may have flown in by mistake.

[Ron]

This! This is my problem. How warm? How long to settle?

Here's "the thing". Two actually. First the dipstick is bad about dragging along the inside of the fill pipe, making it hard to tell where the level actually is. Second, you have to allow the fluid to warm and expand before taking a reading. So, the trick is to start the engine and let it come to operating temperature. Check the level. If none shows, add one quart. Wait for the cool fluid to run down the inside walls of the pipe, (10 seconds ~ 1 minute). When you pull the stick, it should be wet near the end only. If not, repeat. Stop when it shows 1> quart lower than totally FULL. Take it for an easy ~5 minute drive.
At this point, every thing will be full of fluid. It will be expanded and thinner, which helps it flow down the tube faster and not collect on the stick as you insert it. Check the fluid and add to full mark w/o going over. (You can guess fairly well because the distance between the 2 main marks on most represent 1 quart.) If you go over a lot, drain it into a pan from the easiest place you can find (cooler line,..., plug).
From then on, all you have to do is check it (on level ground) after it has been driven a while .

[DrWin]

Do NOT ever take your DeLorean for a "power flush". This is a BS service designed to make money off of soccer moms and Gurus. It could seriously damage your transmission and best case do more harm than good. It's utterly ridiculous to even mention doing this.

Right - I wouldn't want to damage anything, that's basically why I'm asking for pointers about the entire thing.

If you are determined to change all your fluid, my solution (and one that I have been following for the past 3 or 4 years), just drain your fluid every other oil change. The plug is right there, it's no problem to drain and refill without dropping the pan(still do a full service every 12k miles however).

I think that's a pretty good idea. Relative to the rest of the cost of owning, operating and restoring a DeLorean, the cost of the oil and the copper washers is neligable.

Guru disagrees with me when I said to replace what you drained out because it may have been overfilled OK...ASSUMING you have been driving around since the last service not overfilled, you will be OK. If Guru's logic holds, you MUST do a full service every 3k miles because it's possible the trans was last filled with Cheerwine. Also replace your filter because someone may have used a dish sponge instead of a OE filter and as long as we are pointing out long shot scenarios, be sure to clean out all the dead birds from the transmission pan that may have flown in by mistake.

Wait, are you telling me the seagull isn't in the pan for good luck?

[DrWin]

It is impossible to drain all of the fluid out unless you take it all apart. Much of it stays in the torque converter. All Dexron is backwards compatible, you probably won't find II anywhere anyway. It can be difficult to read the dipstick especially if it is overfilled. Follow the procedure in the manual. Don't forget the final drive must be checked separately and uses a different fluid. You cannot take the Renault manual directly and use it for the Delorean. Forget about the temp probe. Do not put back the same amount of fluid you took out, it may have been overfilled. Fill to mid-way between the add and full marks when hot on level ground. If you took the pan off you should either clean the old filter or replace it. Because you can't get all of the old fluid out you *could* go to a service station that has a power flush and have them flush the transmission. They hook up a machine that flushes the old fluid out and fills the transmission with fresh fluid. Best you can do without taking the transmission out and apart. Not really necessary unless your old fluid is very dark and burnt.

Good to know. I get Castrol ATF Dextron II from a speciality dealer, but there is very little point in doing that, it seems. Everyone seems to agree I should step it up to ATF Dextron III and be done with it.
I get that I can't just directly extrapolate from Renault Manual to aplying the same thing on a DeLorean, I just think it's very interesting to make this process more "stringent" instead of how it's descriped in the DeLorean workshop manual.
It feels sloppy, and I never feel confident that I did it right, which anoys me from a prefence perspective, but also because I', assuming that the automatic transmission is a weak/vulnerable/expensive part of the car.