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BillFranklin 07-14-2001 10:52 PM

I found transmission oil flowing from my transmission at the grate under the torque converter. The drain plug is firmly in place. A thousand miles ago I changed the oil and filter in the transmission. Everything seemed normal, and there has been nothing remarkable since then. I walked up the street and found a trail of oil spots that became a solid line then a large spot when I slowed to a stop. Shutting the engine down stopped the flow.
Anyone with a clue would be a great help, as the CD set for 124s includes little on the transmission beyond maintenance.
Is it possible I did something wrong in servicing the transmission?
Thanks to anyone who can offer any help.

dlswnfrd 07-15-2001 12:34 AM

Check it Out
Brother of The benz, Bill
If the transmission didn't leak before your servicing it, then check what you did.
Are the drain plugs tight, both the torque convertor and the sump.
You removed the sump and renewed the gasket. The gasket could be out of position, the capscrews loose, or over tightened.
Could you have over filled the sump? This is always a problem when changing the transmission fluid. Do a close check of the level and possibly remove some fluid to eleminate this item. Better 8 ounces low than 4 too full.
Good luck,
Happy Trails Beep Beep from The Spiderman in Houston!!!

Mike Murrell 07-15-2001 01:49 AM

The torque requirements for your tranny pan bolts are very low.

When one converts the Newton-meter spec., they come up with 6 ft. lbs. approx. Often times, the tranny pan bolts are excessively tightened, resulting in leaks. This is one possibility.

The torque converter uses a copper gasket; the pan uses a silver colored gasket. On one too many occasions, I've been sold a copper colored gasket for the converter drain plug that was just a little too large. Leakage followed it's installation. Make sure that the copper gasket used on the converter drain plug doesn't exceed the perimeter of the plug itself. MB makes 2 small copper washers. You want the smaller of the two. The part number for the copper gasket is 007603-010122. The part number for the silver colored gaket used on the tranny pan plug is 007603-010100. When I ordered 6 of the copper colored gaskets from the local dealer, I received 3 of the larger(wrong) and 3 of the smaller? I've had this also happen when ordering OEM filters from various MB parts suppliers who operate off the WEB. For whatever reason, a Meyle and a Mann tranny filter came with copper gaskets that were just a hair too large. Converter leaks followed their installation.

Mike Murrell 07-15-2001 01:52 AM


The part number for the copper converter drain plug gasket is:


jeffsr 07-15-2001 04:15 PM

If this work was done a thousand miles ago, then one of two things is happening. It was leaking and you just discovered it..or..something nasty just recently occured. If the ATF is coming thru the grate and not tracking from the front edge of the pan(unlikely but possible), then it's either the torque convertor or the front seal on the tranny. Quick diagnosis for you. Get the car up in the air with the engine running (observing all safety precautions). Get a can or two of spray brake parts cleaner with the little red spray attachment. Direct the spray with the little red nozzle thru the grate and spray it on the touque convertor as it is rotating, then spray the grate, the idea is to remove as much residual ATF as possible.. Stand back and observe the grate. If it starts showing fluid right away, kill the engine, rotate the torque convertor until you can eyeball the drain plug. If that's dry, then it either the front seal has blown out or, ug!! something has cracked or broken, torque convertor, front cover or the case itself. It concerns me that you stated that shutting down the engine stopped the flow of ATF which makes it sound like it's pressure related. Try thses things to see if you can narrow it down.. Good Luck.

BillFranklin 07-16-2001 02:59 AM

transmission leak, '89 300E
Jeff Lawrence seems to have the best answer, so far. Local shop says most likely the front pump seal and o-ring: $5 in parts,eight hours labor. There is a possibility that another, easier-to-repair leak may be the problem, but they have not yet put it on the rack.
I'm told that the problem I described is usually the front pump seal, as long as the drain plugs are tight(FWIW to all of you).
Thank you all for your consideration and response.

Late breaking news. This just in: I damaged the trans myself by backing for a great distance (1/4 mile, perhaps) a few days ago.
I have never had an automatic transmission before, and have never before heard that there are such limits on the use of reverse gear. My shop tells me that is the problem without a doubt. For anyone as ignorant as I was, it may also be useful to know that these transmissions will heat up so much when idling for a long time that the front pump seal will literally melt.

[Edited by BillFranklin on 07-16-2001 at 06:28 AM]

jeffsr 07-16-2001 03:14 PM

Well, pardon me, you backed up 1,380 feet and fried the front seal. How fast did you go. The 722.3 has a rather low gear ratio for reverse, so unless you had it floored (I hope not), I can't see how you trashed the front seal. Just suppose you drove into the woods on a narrow road and found yourself a mile or so into the forest. if you consulted your owner's manual, would it tell you to avoid narrow roads or forests. If you kept the rpms reasonable, I can't see how you could destroy the front seal, unless it was scheduled to fail anyway and you found it in your heart to finish it off. BTW, I have never heard of a seal in a tranny melting from sitting at idle. I suppose it's possible, but I suspect that if it did happen, a lot of other things would be melting as well. I think someone is blowing smoke up your to speak..:):):)

Mike Murrell 07-16-2001 03:32 PM

Get ANOTHER opinion!!! I'd like to say what I think about what you were told, but I'll restrain myself instead.

BillFranklin 07-17-2001 03:46 AM

transmission leak, '89 300E
Thanks to all of you who provided help, suggestions, and pithy remarks. This forum has been a great source of information to a shade-tree mechanic trying to keep up an old car. Pithy remarks are usually at least as helpful as other replies, just not for those with thin skin.

The Xmission has been repaired with the replacement of the front pump, no seals were damaged. If I knew enough about
automatic Xmissions, I would give you more details.

Regarding the melting seal, the advice given was that, with the car in DRIVE, the transmission tends to get overly hot while sitting still, as in stopped traffic. The advice continued to recommend putting the Xmission in PARK or NEUTRAL as much as possible at these times.

Again, thanks for your responses. Since most of you probably know a lot more than I do, you are a very valuable
asset. I have no local contacts who can give such well-informed advice.

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