Transmission fluid dipstick mystery - PeachParts Mercedes-Benz Forum

cmac2012 · #1 06-02-2025, 04:52 PM

I can't tell you how many times I've searched trying to come up with an accurate figure on how much fluid is required to raise tranny fluid level from minimum mark on stick to full mark on the stick. Adding a little bit and checking it immediately is a non-starter. It takes, I don't know how long, but some of engine vibrating for all the excess fluid in the tube to drain down to the tranny. After you have put in even a little bit, you can't get an accurate reading on the stick until later, maybe an hour later.

You would think that somewhere, somebody knows, that for example the amount of fluid represented by the space between marks would be 1 pint. Or maybe 1/2 pint or maybe let me see, 250 ml, which would be slightly less than 1/2 pint. I hate adding what seems like a few fluid ounces only to find that the new tranny level is way too high the next time I check it. Why is this so goddamned hard?

I am coming around to a firm commitment to finding a five speed euro 123 tranny and installng it. It would be such a pleasure to have control over a tranny that wasn't constantly threatening to self-destruct.

nelstomlinson · #2 06-02-2025, 11:16 PM

That's an enormous pain on every auto trans! Why can't they mark it "add one pint," or whatever, right on the stick?

ah-kay · #3 06-02-2025, 11:26 PM

Your transmission is not going to die when it is a tad above or below the mark. It is not rocket science and measured in milli litre.

The valve body takes up a lot of volume so adding a small cup would raise the level big time. I normally add a small cup and wait awhile, next day normally, to check the level. What I did is to get the level right on ( with engine running ), turn off engine and check the level next day when the level settles. It will be higher than the full mark. I make a mark on the dip stick and from then on I check the level without the engine running. The mark would be my overnight level, just like oil level. Good luck.

Marshall Welch · #4 06-03-2025, 01:36 AM

Here is a summary which I might have condensed from the original text; I have it printed on a 3x5 inch card for easy reference; the source is listed below:

“2710 - Automatic transmission, checking, correcting fluid level.

“Check:
- Apply parking brake
- Place selector lever in P
- Run engine for 1 to 2 minutes

“At operating temperature (80 degrees C), should be at maximum level mark.

“At 20 - 30 degrees C, 722.3_ transmissions will read 10 mm below minimum level mark.

“Add necessary amount of fluid through funnel into dipstick tube with engine running.

“Note: The distance between the min and max mark on the dipstick is approximately 0.3 liter of transmission fluid.

“After filling fluid to specified level, apply parking brake. Move selector lever through positions R-N-D-N-R, pausing for a few seconds at each position, and return to P position, to ensure that the operating pistons of the servo members are filled with fluid. Recheck fluid level, and correct, if necessary.”

Reference:
Mercedes-Benz Maintenance Manual USA, Model Year 1981-1993. Maintenance Manual USA Supplement 3 - February, 1991.

I’ll check the pdf tomorrow and confirm; it’s on my desktop computer, which I’m away from now. I’ll post any correction if needed.

Edit to add: The reference listed above comes from https://mercedeslist.com/serviceindex.html. Click on the Read Me link at the site for more details and instructions.

Edit #2: It looks like the information above is accurate. Attached is a copy:

Diesel911 · #5 06-03-2025, 01:52 AM

Quote:

Originally Posted by cmac2012

I can't tell you how many times I've searched trying to come up with an accurate figure on how much fluid is required to raise tranny fluid level from minimum mark on stick to full mark on the stick. Adding a little bit and checking it immediately is a non-starter. It takes, I don't know how long, but some of engine vibrating for all the excess fluid in the tube to drain down to the tranny. After you have put in even a little bit, you can't get an accurate reading on the stick until later, maybe an hour later.

You would think that somewhere, somebody knows, that for example the amount of fluid represented by the space between marks would be 1 pint. Or maybe 1/2 pint or maybe let me see, 250 ml, which would be slightly less than 1/2 pint. I hate adding what seems like a few fluid ounces only to find that the new tranny level is way too high the next time I check it. Why is this so goddamned hard?

I am coming around to a firm commitment to finding a five speed euro 123 tranny and installng it. It would be such a pleasure to have control over a tranny that wasn't constantly threatening to self-destruct.

If you are speaking of a manual transmission conversion what comes up is the issue of where to get a flywheel. There is older write ups on that.

There is a lot more 4-cylinder flywheels out there compared to 5-cylinder ones.