Satan's 560SEL - PeachParts Mercedes-Benz Forum

tram · #1 02-07-2009, 01:04 AM

Sometimes you just have to laugh.

A friend of mine with a 1990 560SEL calls me up about a month ago. He says their 110K mile creampuff 560 suddenly lost power, started shaking, and barely made it home from the corner store. I tell him to start with a tune- up as it sounds like maybe it flooded and only runs on a few cylinders.

Fast forward to yesterday- Still same issue, so I tell him to go ahead and tow it up.

Winds up that the engine sounds and seems to run fine, BUT runs like "Whup- Whup- Whup" as the car tries to hop like a Southern California funny car. Further checking shows that reverse works fine, but Neutral wants do do a hopping, lunging reverse, and the forward gears act like there's no trans fluid in the trans, and the car hops forward slowly like it's got a badly bent propeller shaft. In Park, it hops backwards until the parking pawl kicks in, then it does the Jumping Bean trick.

While checking basic settings, I notice that the RPMs aren't changing hardly at all- it REALLY feels like the trans is being quickly and rhythmically shifted between "park" and "reverse".

No vacuum leaks. Brakes are free. Trans fluid level is correct. No leaks. Trans fluid is clean. Drive shaft, rubber discs, joints, and bearings are all good. Propeller shaft and drive axles are dead straight. Shift linkage is adjusted perfectly and bushings are good. The neutral safety/ reverse lamp switch is functional.

It acts like the trans is stuck in reverse... all the time. In Drive, it's a two steps forward, one step back experience. Amazing.

So...

1) Transmission internals are one thing I'm not trained in. And, of course, I have three factory volumes on this chassis and this engine. Guess what they don't cover? Nice.

2) Transmission experts: Is this some common stupid thing that can be fixed? Crap in the valve body? My gut tells me that it's time for a transmission and torque converter transplant. Problem is, you can buy another 560 for less than the cost of doing it right and the shipping on the trans, converter, and cores.

3) I have a buddy with a pretty much junk 1984 380SE. The trans on this car is about the ONLY thing good. Can this be installed in the 560? What are the fitment issues, and what are the downsides to doing this? I know they're two different transmission numbers, but they're the same family.

Ideas? Thanks in advance.

tram · #2 02-07-2009, 11:47 PM

WOW. Anybody?

Can anyone at least tell me if the 1984 380SE transmission swap is do- able?

Johnhef · #3 02-08-2009, 11:30 PM

Dont think so, for one, no cut out in the bellhousing for the crank sensor.

pawoSD · #4 02-09-2009, 12:27 AM

Sounds like something bad happened to the trans or torque converter.

How does it cost more than the car? You can get a shop to rebuild a trans for $1000ish.....

wbain5280 · #5 02-09-2009, 01:30 AM

There are two shift linkage bushings that may need to be replaced.

pawoSD · #6 02-09-2009, 07:18 AM

You've tried putting the gear selector in all positions? Even all the way down to "L" (or 2) ?

TheDon · #7 02-09-2009, 10:01 AM

run the vins on both cars to get the tranny numbers. If they match swap them, if not look into what you can do with the 380's transmission.

Tram from thesamba..nice

david s poole · #8 02-09-2009, 10:10 AM

the 380 trans will not swap.sounds to me like the springs and plate[that returns reverse piston to off]may have come apart.i have seen many strange things caused by valve body faults but this is not one of them.pull out trans and remove front pump assembly and you should see problem.

tram · #9 02-09-2009, 01:04 PM

Thanks David. That sounds like "it".

TheDon: Hey, Man! What it is?

pawoSD: Yes, I've tried everything. As to your cost analysis: In my area, everything I've hired out- no matter what- I've wound up redoing. Competence is not a strong point in this area. Like I said in my previous posts, auto trans is about the only skill I lack. So, replacement with a rebuilt is about the only option. $2200 (at cost) for reman trans and torque converter, plus freight, plus return freight on cores, plus labor... out here $2500- 3K will buy a NICE 560, because our economy is horrible.

wbain5280: Yes, shift bushings and all external controls are in great shape.

Johnhef: D'oh! Good point!