Stupid ATF question - PeachParts Mercedes-Benz Forum

Tree Frog · #1 06-01-2006, 10:02 AM

Okay, at the risk of sounding like a complete idiot, here goes....

I changed my auto tranny fluid and filter in my 82 240D. I'm not a natural born mechanic, and don't work under a shade tree, so I now have a question that I'm sure this robust group can answer.

How the heck to you get teh proper level of fluid back into the tranny?

I got everything sealed back up and started pouring the atf back in. So far so good, until I checked the dipstick. Too much. So I drained a little. Oops, need a little more fluid. Poured more in, then checked again...too much. Drain, check, not enough. Poured more in...looked about right. Then I cranked the car up to check (per the instruction manual). Not enough. Added more...now too much.

Obviously, I'd rather not continue this dance with my tranny fluid. Can someone offer a better method?

I can't tell how much fluid came out of the tranny originally due to all the draining and refilling.

At least my injectors will be happy.

Thanks in advance.

rs899 · #2 06-01-2006, 11:35 AM

You did not say if you had drained the torque converter.

IF you had drained the TC, I would suggest you read the system capacity in your manual , dump in about 90% of that and drive until you heat the system up, then check and add fluid per the manual.

Without draining the TC, you are probably doing as well as can be expected.

Rick

Maroon 300D · #3 06-01-2006, 11:42 AM

I had a heck of a time reading my tranny dipstick recently. I started a thread about it and it got like 20 replies, so you are not the only one who has had trouble with it. Many others have found it hard to get it exactly right.

1983/300CD · #4 06-01-2006, 11:47 AM

Car needs to be...

Hot,
Level,
Running,
In park.

SD Blue · #5 06-01-2006, 11:51 AM

These trannys seem to be very sensitive to fluid levels. Be sure you are checking the system hot and running in park. If you are adding to a hot tranny, cycle through the range of the shifter, at a minimum, to ensure the level stabilizes.

Even with this procedure, only fill to the minimum level until you have done another good driving test. Then add about 50ml.

PatricdeBoer · #6 06-01-2006, 01:22 PM

When I refilled the SD's tranny I did it cold. I got it right up to the bottom line and once the car heated up, it rose right to the middleof the two. It's a PITA to get an accurate reading sometimes.

sailor15015 · #7 06-01-2006, 02:37 PM

I usually check mine right before I wash my car. Its about five or so miles to the carwash, on the highway so the engine gets up to operating temps. I pull up, leave it running, and go get change. By that time its been sitting for a minute or so. I run it through the gears, put it back in park, then get out and check the level. Its been right below the max mark the last couple of times I've checked it.

rhodes2010 · #8 06-01-2006, 04:02 PM

You really need to put it in gear (reverse and forward) to absorb fluid
into the system. Then recheck, as stated, hot/warm and running and
reasonably level.

I have never had to remove fluid, I do know that right after dumping some in it
reads way too high, but I drive it a little and it drops back down.

I have wondered if it did not stick in the dipstick tube somehow and give false
readings. Either way, add a little, drive a little, check fuild.

Would anyone here agree that a little high is better to okay than being too low ?

Maroon 300D · #9 06-01-2006, 05:49 PM

Quote:

Originally Posted by rhodes2010

You really need to put it in gear (reverse and forward) to absorb fluid
into the system. Then recheck, as stated, hot/warm and running and
reasonably level.

I have never had to remove fluid, I do know that right after dumping some in it
reads way too high, but I drive it a little and it drops back down.

I have wondered if it did not stick in the dipstick tube somehow and give false
readings. Either way, add a little, drive a little, check fuild.

Would anyone here agree that a little high is better to okay than being too low ?

It will definitely stick to the dipstick tube. The problem that I had recently was that it was reading too high, so once I figured that out, I started draining a little bit each day using a brake bleeder kit and the car's own vac pump. After I would do this I couldn't get an accurate reading, though, because of the sticking along the sides of the tube issue, so I wound up doing this a few days in a row.

The general consensus on this site seems to be that it's actually better to be a bit low than high due to foaming issues and the reduced lubrication that results. The guy who re-built my tranny told me that mine has vents, though, so it won't hurt it to be high. It was actually WAY high when I started draining it and probably had been for a year, so I believe him. It's unclear to me whether he actually created the vents or if they were already there when he worked on it (my girlfriend took it into the shop and the PO had the work done).

As of now my fluid level is still a bit high, a half-inch or so on the dipstick, and the car is having some trouble shifting into third on cold mornings. Once it gets hot it's fine, though. I'm not going to add fluid to get it back to its previous level, which was 2 inches or more high.