New Guy here need help with W140 S600 Transmission - PeachParts Mercedes-Benz Forum

WaldS600 · #1 08-01-2006, 01:14 PM

First off I must say, I love this site for the great technical info. I have recently picked up a 1991 European model S600 with 86 km on the clock (basically about 54k miles)

I had a few problems initially with loss of power and poor shifting. With the help of this site, I did the following

1- oil and filter change
2- new plugs
3- new k&n intakes
4- fluid and filter change for the trans
5- new cats (old ones were plugged very badly)

After all of that, the power seems to be back. I do get an intermittent ASR light but that I will deal with after

The main problem is the transmission. Before fluid and filter change, the transmission would flare quite badly between gears. After fluid change, it seemed to grab well. Reverse was fine, and forward gears seemed ok. It would still flare slightly and it would seem to skip gear 2 and 3. It would feel like it was going 1st to 4th and the shifts were quite hard

After a few days it seemed like I was getting a little leak from the pan. I used new gaskets, but I was getting a slight drip. After a few days, it seems like my transmission won't engage gears at all. It will shudder when trying to select D, 3 on the shift gate. First gear seems to work, but every other gear is like neutral.

When I hit bumps, it sounds like I can hear the gear linkage disconnected? There is a heavy rattling around underneath the gear lever area. I know my bushings are absolutely shot, but would this be any cause or perhaps not being able to select any gears?

I have read most all the transmission threads. I have not checked for vacuum leaks, and I read about a stuck kickdown switch, but it seemed fine.

The shop now is telling me that I need a new transmission which I find slightly unusual at such low kms. There were no shavings or anything when I dropped the pan to change the oil. Then again the car is 15 years old.

After I found a little leak, I tried filling it with a bit more ATF, but now it seems that I am leaking a lot more fluid and it is smoking on the exhaust.

All help with all this would be greatly appreciated!

softconsult · #2 08-01-2006, 02:15 PM

"When I hit bumps, it sounds like I can hear the gear linkage disconnected? There is a heavy rattling around underneath the gear lever area. I know my bushings are absolutely shot, but would this be any cause or perhaps not being able to select any gears?"

This has to be one of funniest paragraphs I have read in a while.

Steve

865sp300e · #3 08-01-2006, 02:25 PM

Quote:

Originally Posted by softconsult

"When I hit bumps, it sounds like I can hear the gear linkage disconnected? There is a heavy rattling around underneath the gear lever area. I know my bushings are absolutely shot, but would this be any cause or perhaps not being able to select any gears?"

This has to be one of funniest paragraphs I have read in a while.

Steve

I agree, this one is a classic.

WaldS600 · #4 08-01-2006, 03:49 PM

it is funny, but can anyone help me?

meltedpanda · #5 08-01-2006, 03:50 PM

too much fluid will come out on its own and can cause poor performance. Did you overfill?
If not, it does sound like your tranny is going south or in need of serious adjustments. I doubt your linkages are loose and making noise as you describe Take it to an indep mech that specializes in vintage MB's
Let us know where you are and we can assist in locating one for you

WaldS600 · #6 08-01-2006, 03:53 PM

is that common to have these major problems with such low mileage?

What I am trying to figure out is if the unit actually does need replacement

or if there are adjustments that can be made to save this trans

softconsult · #7 08-01-2006, 04:13 PM

Seriously, any Mercedes, if not maintained over the years can be an absolute
money pit. A '91 S600 V12? I shudder to think of the money this car could consume just on routine maintenance, let alone transmission replacement.

The car cost north of $100,000 dollars and is now 15 years old. Low mileage can be worse that normal mileage because the car must have sat around a lot.

There was a post on another list last week written by a shop owner concerning an S600 disaster. A $30,000 repair as I recall. If I remember correctly, they generally refuse to work on the 600's.

Not trying to bring gloom and doom, but you better have deep pockets!

Steve

meltedpanda · #8 08-01-2006, 04:17 PM

not really, are you sure it has not been around once/twice?

It may be hard to find an indy to look at it but that is what I would do
The W140 as nice as they look are notorious for electrical gremilins and a host of other issues. One needs deep (very) pockets on the ones that go south. Many however have had good luck, so hope is not lost.
Any repair records?
MY guess would be vacuum issue, but I am not sure that would account for the noise you are hearing.
I am sure others will help here,

comon guys/gals newbie needs help.

.

WaldS600 · #9 08-01-2006, 06:06 PM

most of the major work had already been done recently. 2 new ETA's, new wiring harnesses,a/c has been upgraded

C32AMG · #10 08-01-2006, 09:43 PM

Fix the linkage bushing problem first, once the shifter linkage is aligned and working, check the fluid level and adjust as necessary, then road test the car and post your findings.

A. Rosich · #11 08-01-2006, 10:13 PM

I really don't want to rain on your parade, but I sincerely believe the mileage on your car is not at all real.

S 600s in Germany and Europe, like all V-8s also, are well known to be bought by owners who cover thousands of miles every year (at least most of them do). A 1991 with only 86,000 kms sounds extremely suspicious to me, more so when you mention plugged cats AND your transmission behavior.

By just those two facts, I would say you car has easily 386,000 or 486,000 kms. If you got an stamped service booklet, frame it. In Germany they sell stamped maintenance booklets around corners like they sell fake Rolexes in New York. The odometers of pre-facelift W140s are very easily altered. I have seen importers here take off 200,000 to 300,000 kms. off analog odometers in a blink. They do it on digital ones too, although it just take them a little more time.

Hence, and guessing maintenance was not at its best during its service (from the reference of the cats), the transmission just had it and it looks like your car is a prime candidate for a new one. Sorry!

C32AMG · #12 08-01-2006, 11:06 PM

I did not what to say it but since the cat is out of the bag, grey market/ euro cars Imported into other countries have higher mileage then shown, the clocks were turn back.

WaldS600 · #13 08-02-2006, 05:15 AM

i am aware of the odometer rollback but i make sure i get cars that are inspected by one of my own guys. i have another car with 45k miles that is absolutely perfect and problem free from 1990.

The interior on this s600 shows barely any wear. And wouldn't really make sense if it had 200 or 300k miles on it. The exterior is all original paint and isn't in terrible shape either.

I have seen, driven and owned cars with 150k to 300k plus and they are definately bagged in every sense.

This car only had a combination of minor issues and I am trying to diagnose the transmission as best I can. All the other issues have been resolved, and were merely standard maintenence fixes

also on a few sites, I had read that cat converters are only good for x amount of years, and approx 80,000 kms before they can fail. It can also be attributed to faulty oxygen sensor, an incorrect fuel

mixture, worn spark plugs or plug wires, a faulty check valve, incorrect ignition timing, sticking float, faulty injectors or other ignition malfunctions.

The car had one 02 sensor that was ripped out on the side of the failed cat, as well as worn spark plugs. The rest was fine upon mechanical inspection

suginami · #14 08-02-2006, 04:15 PM

I would listen to C32AMG's advice.

He is the owner of a transmission rebuild shop.