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1982 380SEC, 2003 S600 v12tt
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11 Posts
Discussion Starter #1
Bought a 1990 560SEL with 200K miles last month (with low expectations for what I was getting). Previous owner had changed tranny fluid and filter and had driven less than 100 miles with no problems, and fluid tested as at the correct level. I drove the car about 40 miles from the seller's home to mine (some back roads and interstate), no tranny issues noticed. Engine had a misfire, which I spent a few days diagnosing and correcting.

First (attempted) drive after fixing the misfire, I backed out of my driveway, drove about 50 feet, stopped at a stop sign, and went no further. No forward gears, and no reverse. The tranny shifted into park with no problem, and shifted back into reverse and drive but the car would not move.

I put the car on the lift in the garage and cranked it. When shifting through the gears, the drive shaft moves very slowly, and the rear wheels turn very slowly, although I can stop them turning with my hand. Revving the engine makes the drive shaft and wheels turn a little faster, but still can be stopped with hand pressure.

After many hours of forum searches and Youtube videos (thanks to everyone out there who has posted so much helpful content), I found the vacuum modulator valve would not hold vacuum, and appeared to be allowing tranny fluid to be sucked into the intake through the vacuum line. I installed a new M-B valve, but this made no difference in the tranny problem.

Am I missing something obvious/cheap? Thanks.
 

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Registered
1982 380SEC, 2003 S600 v12tt
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11 Posts
Discussion Starter #4
So was this a really lame question (highly likely), or have I stumped the panel (seems unlikely)? My next step is remove the tranny and take it apart. If it's shot, I can't make it any worse, and it might be a good learning experience.
 

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1991 560sec. 1969 280SL
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966 Posts
I haven’t heard of torque converter problems with these but have heard of many b2 piston failures (on side of trans).
 

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Registered
1982 380SEC, 2003 S600 v12tt
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11 Posts
Discussion Starter #6
Several threads deal with piston failure, and the subsequent loss of reverse or forward gears, but typically not both. That's what has me stumped.
 

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'87 560 SEC, Pearl Grey/blue; 300,000+ mi; '07 CLS 550, Barolo/stone; 90,000+ mi
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412 Posts
Yes, my torque converter went at around 312,000 miles (and I had the transmission rebuilt at 249,000 miles).
 

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1999 E430; 2005 ML500
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1,494 Posts
Something tells me you will find the tranny in need of a rebuild. He probably ran the fluid low and burnt the clutches. Since he changed the fluid, you find no evidence.
 

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1982 380SEC, 2003 S600 v12tt
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11 Posts
Discussion Starter #9
Is it typical for the clutches to go all at once? If so, that sounds like a strong probability. I disconnected one of the lines to the radiator to test the pump, and it blew fluid all over the garage in just a few seconds!
 

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1990 420 SEC
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103 Posts
There used to be a lot of info on transmissions posted by member HATTENATOR elsewhere on benzworld. Unfortunately everything he posted via Photobucket is now blurred and not readable. This would have been very useful thread:
I do not think he is active anymore. Have you tried driving car on first gear? On D it starts on second. I do not know if second and reverse have a common brake or clutch that needs to be engaged.
 

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Registered
1982 380SEC, 2003 S600 v12tt
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11 Posts
Discussion Starter #11
Thanks for that link, I'll read through it. I've tried the the shifter in all positions with no luck. Although, with the car on the lift, the wheels will turn very slowly but can be stopped with hand pressure. It also goes into and out of park, locking and unlocking the drive shaft, so I know the shift linkage is connected.
 
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