Auto Trans overfill - PeachParts Mercedes-Benz Forum

JHZR2 · #1 01-30-2003, 02:29 PM

Hi,

I swapped the fluid/filter in my automatic transmission, including torque converter, and put in new dexron. I did as the manual stated, adding the quantity of fluid for fills after initial, and went off on my way. I drove it a bit, and noiticed a new odd thing happen when shifting. The first shift, the revs increased a tiny bit, and then got to the new gear. The second shift, around 2000 RPMs, started to go, then the revs went up to 2500 then it finally got the gear, I guess, and stayed at about 2000 for a while as I accelerated, then went up.
I drove for a while like this, thinking maybe the fill amount assumes capacity in the ATF cooler, etc., so I drove it for proabbly 20 miles (including a highway bit, where I took the car up to 85). Some shifts were weird, some were better (partially depending on how hard I drove the car).
I stopped after a while, and checked the level (worrying that maybe I needed more. To my disgust, I saw nice red ATF with little air bubbles in it, and very high... nowhere near the two lines. The level was about 1/2 inch below the first two bends in the dipstick!
So I dont know how much capacity the corresponds to, but regardless, I have severely overfilled it. None has leaked, and I drove some more to do things and came home.

I know I need to get rid of some of the fluid. My question is, being that it looked like there was air in the fluid, and being that I drove it a while even at very high speeds, is the fluid ruined? Its still a nice red color. Can I just suck some out then add slowly some mobil 1 (I like the idea of having a bit of synth in it mixed with my dino ATF)?
Whats the chance of my trans having damage or shortened life from driving it overfilled for 60 or so miles?
I would liek to buy one of those cheap 99c siphons from autozone (its cheap and disposable, and hopefully as clean as it gets) and start sucking some out. I figure by the time the oil fills the long tube length, and is starting to drain out, enough ought to be removed, and then its trial and error. ANyone see any problems with this?
Thanks for your help.

JMH

rwthomas1 · #2 01-30-2003, 03:38 PM

The fluid is fine. Remove the drain plug and drain off about a quart. Test drive and check again. i have found that filling to the bottom line on the dipstick when cold will be just right. When warm the fluid will be almost to the top line. RT

leathermang · #3 01-30-2003, 06:14 PM

I don't know if it is that slam dunk of an answer.. You don't want it to get overheated and you don't want to oxygenate it.. with it really overfilled you may have drastically reduced its effective longivity...by foaming it...
I would ask this... how much would it cost to just change the fluid ? the filter would not be harmed by that mistake.. so would it be better to change out the fluid just in case or leave it?
I read about temp/life of transmission fluids and was astounded at how little of some activities it took to HALF the life of the fluid... like when stuck in the mud going back and forth from drive to reverse for four minutes could cut it in half.. those sorts of figures... of course that was 20 years ago... but on the other hand your car is that old also... I don't know.. seems a cheap fix to replace it with new and write it off to a learning experience....

JHZR2 · #4 01-30-2003, 06:29 PM

hmmmm, OK, well, good point... remove as much as possible it is then. I will be working in my snow-covered parking lot, so droping the pan is not an option, I really want to take it from the dipstick hole. (The toirque converter couldnt be drained via the plug or dipstick anyway).

Any idea how much fluid I should expect coming from the pan, out the dipstick hole? I would guess around 4 qts?

I plan to use the rest of my Mobil 1 ATF (I have maybe 1.5 qts) and mix in some more quaker state (which is what is currentl in it) Sound OK???

Thanks again

JMH

rwthomas1 · #5 01-30-2003, 08:16 PM

I say just make it the right level and let it go until spring. Too damned cold to mess with it now. We don't all have the luxury of great weather to work on our cars like Leathermang does....

Slam.......................Dunk!
RT

leathermang · #6 01-30-2003, 09:03 PM

It is true I was not figuring in the weather.. on the other hand how bad would a total failure of the trans in (still) cold weather be?

Gilly · #7 01-30-2003, 10:03 PM

From the initial post, I am seeing a problem. Maybe.
You should drain the pan and torque converter, change the filter, and seal everything back up. Then put in the initial amount before starting, about 3 quarts. Then start the engine and finish filling the transmission. Most 722.3/.4/.5 transmissions take from 6.5 up to around 8 quarts, depending on model.
If you only put in the initial 3 quarts or so "and drove off", then you are way low, which may explain the odd shifting and air in the oil.

Gilly

190D22 · #8 01-30-2003, 10:53 PM

I did the same thing recently. Just I didn't over fill it as high as u did. Mine begain venting out the excess fluid. I drained it and put in 2 quarts, started it up, let it run a bit, and rechecked the level. It was perfect. I drove it and checked again, still perfect level, and no fluid being vented. 2 weeks later, all the previous was still true, and is still true today. Shifts perfectly. Shifts like it has old seals... what a coincidence! But it shifts fine, very crisp.

M. Theofanides · #9 01-31-2003, 01:30 AM

I did the same thing a year or so ago, when I replaced my radiator. I was on the highway and on my way to catch a plane when I found out that I had to much fliud. It was pumping it out the vent tube on the exhaust, so I had to do some thing. I just removed one of the lines going to the trans cooler and had my wife start the car and let it run until it pumped out a pint out, into a bottle of course.
It has been 30,000 now with no ill effects.

good luck

lrg · #10 01-31-2003, 01:50 PM

I've got to agree with Gilly that the bubbling sounds to me more like underfill than overfill. The fact you saw bubbles high up on the dipstick doesn't automatically mean an overfill, especially if the fluid is foaming. I think the advice to drain everything, including the torque converter, and start over is best. Follow the factory fill instructions to add a few quarts, idle the engine a bit, then add the rest to bring the level up to the proper point on the dipstick.

leathermang · #11 01-31-2003, 01:56 PM

BUt RT thinks it is too cold ! ?

Why do yall live up there in the cold anyway... We have room down here... ( it is 70 degrees rignt now ) Come ON Down !

Holson Adi · #12 01-31-2003, 02:00 PM

I agree that it did sound more like not enough ATF because I did the same and my tranny slipped a bit.

Topped it up and it's been fine ever since.

rwthomas1 · #13 01-31-2003, 02:03 PM

Hey Leathermang,
I lived in Austin for 5 years and I loved it. Got caught in the high-tech crash in '01 and was laid off. Free place to live back here in RI so this is where I am now. Believe me, there aren't any jobs here either so I am looking someplace warmer again. You Texans think you have it rough with temps in the 30-40* range. We just got past two weeks of temps hovering at 0* and windchill in the -20*s..... Its actually dangerous to be outside under a car in that kind of weather. No car is worth frostbite. RT

Gilly · #14 01-31-2003, 08:01 PM

LRG:
To clarify what you said: Put in about 3 quarts, start engine (leaving it running), then add the rest of the fluid. Don't put in 3 quarts, idle it a bit and shut it off, and then add the rest. Leave it run after putting in the initial 3 quarts.

Gilly

lrg · #15 01-31-2003, 09:48 PM

Gilly,
Your description is much better and what I meant but described poorly, thanks.

JMH,
The reason you start with 3 quarts and add the rest while idling is to properly fill the torque converter after it has been drained. If you don't do it that way the torque converter doesn't fill up properly and the oil (assuming you filled to the correct amount specified for a fluid change) can overflow, ultimately leaving you with low fluid. This may in fact be what happened to you if you just filled it up and drove.