I brought my 91 300D 67k in for a transmission and filter service (Mobil 1), and drove the car home 7 miles. The car was slipping and clunking at shifts when I reached the house. The car NEVER did this before the change.

I immediately checked the fluid, and it was nearly 2 inches above the full mark.

I drained the entire transmission using a topsider in the dipstick tube, taking out 2.3 gallons of fluid, way too much, and who knows how much is left in there that the topsider didn't get out.

My question is, would such an overfill cause the transmission to slip and act clunky? I thought repair shops were supposed to repair, not destroy!

Any advice for me before I put the correct amount of fluid in and try it out?

John Peterson

The transmission is designed to work using fluid, not foam.

Overfill can allow air to be mixed with the fluid, making it act thinner. Pressure may not build up as fast on pistons, as the air is compressible.

Restore, or better yet have go back to the shop that did the change and have them restore the fluid to its proper level and the transmission should once again act like it did before.

The first step in solving any transmission-related problem is always ensure that the level is correct but you already knew that...

Best Regards,
Jim

Make sure when you read the transmission dipstick that the car is on level ground. Also, make sure that the car is up to operating temperature before you check. This way you know that your readings are correct.

I'm going to bring it back to the shop -- or tow it in.

The transmission worked perfectly before their screw up- do you think this will have caused perm. damage? Should I call my lawyer?

Thanks friends.

John Peterson

Whatever happens make sure you save your reciepts and make sure whatever they do is put in writing...............its possible damage was done.....or its life was shortened............but you can always get lucky.

__________________
Proud owner of ....
1971 280SE W108
1979 300SD W116
1983 300D W123
1975 Ironhead Sportster chopper
1987 GMC 3/4 ton 4X4 Diesel
1989 Honda Civic (Heavily modified)
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Section 609 MVAC Certified
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"He who fights with monsters might take care lest he thereby become a monster. And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche

Samito,

I may be that they added 6 quarts without draining the torque converter.

But they should have checked the dip stick before turning the car back to you.

WHy did you remove the overfilled fluid and lose your evidence?

P E H

To make you feel a bit better, there is very little they could have done to ruin your transmission in such a short time by just changing the oil and filter, especially when you say that the symptoms started IMMEDIATELY after they completed they work.

The most possible cause is that that they may have inadvertently disconnected a vacuum line near the transmission.

Another possible cause is fluid related, and there are three possibilities:

1) Substantially Over-filled
2) Substantially Under-filled
3) Wrong Fluid.

I would bet on a Vacuum line being disconnected, but in either case I doubt that any permanent damage would have been caused.

Phil

__________________
'95 E300 Diesel, 264,000 Miles. [Sold it]

Guys,

Transmission question. How often should it be changed in my 90 350sdl? according to the records, it was changed 50k miles ago. however, i looked in the dipstick and it still looked rosey red in color.

The reason I bring this up is because it sometimes 'slips'? in the morning (not sure if that is the term). In the first 200 yards of driving the car sometimes will quickly rev past 4k and then quickly go back to normal revs. After that, it is fine.

How much should i expect to pay for indy tranny service?

It's a fine car especially for what i paid for it.

Any transmission gurus here?

__________________
Jennifer
90 350sdl

I would change the fluid and filter now. If you don't want to do it yourself, many of the "quick lube" operations will do a "flush" for around $80. They use a machine that replaces the old fluid with new. As I understand the process, the machine tells them if the filter needs to be replaced. They claim that their process removes more of the old fluid than just draining the transmission and torque converter.

JenTay,

You could do it yourself for about $40 with new filter and Mobil 1 synthetic ATF. Its not rocket science.

P E H

JenTay, change fluid and filter and while you are at it install a new K1 kit. You can get this from the MB dealership. Your transmission is flaring (the RPM jump gives it away). The kit I believe is somewhere around $10 and can be replaced with the trans. in the car. Do a search on K1 here and you should get the info. you need.
Also, get the part # for the kit. My MB parts guy looked at me like I was nuts when I ordered it. Had to give them a parts #. He said he had never ordered one of these in all the years he had been there (over 30). Makes you wonder how many transmissions in this town have been replaced needlessly!

Hi JenTay,

I believe that your car, like my 86 SDL, has a shift 'softener' which applies more vacuum to the vacuum modulator when the engine is cold, thereby making the shift softer.

It's possible that the modulator is giving overall shifts that are too soft, and it's most noticeable when cold, or that the vacuum valve is applying too much vacuum at a given pedal travel.

Mine flares pretty dramatically for the first 3 or 4 shifts when cold, then settles down.

By all means change the trans fluid, and figure if it's still too soft when the engine is cold, it might need some other adjustments.

Best Regards,
Jim