transmission woes
 

Hi all,
Automatic transmission suddenly stopped working.
No reverse no drive... nothing. Had to get towed home.
The linkage from shifter to trans is connected fine.
Fluid level good.

I read about people having the same symptoms with the staked nut to the tranny output flange going bad.
I dropped the driveshaft and the staked nut and output flange look good and are tight. No looseness at all.

What's my next move?:(

Thanks,
Jeff

I'm getting a rebuild.

Probably is most likely main pump failure. If you have to drop it, might as well do it only once.

Marc at Sun Valley has one on the bench for me right now...

I bought a car with the exact same issue. No movement in any gear. I used the car for parts, and never figured out the problem with the trans. I did check for fluid flow to/from the cooler, and flow was present. I was told that if there is fluid flow, the pump is good. As far as MB trans rebuilders, there is none better than Sun Valley Mercedes Transmissions. Marc is a great guy, and he knows his stuff when it comes to MB transmissions. You won't be disappointed with any work he does......Rich

Thanks for the replies. A few years back I pulled a manual tranny
from a Euro 300d. I've even got the bigger (38 lb?) flywheel for the 617 engine.
It's just sitting here. Hmmm....maybe it's time for the W126 manual tranny conversion.

What do you think???

Jeff

I think it is a great idea. I too have a car ('82 300CD) that has no fourth gear. I have a complete 4 spd setup from a 240 that I am thinking about swapping in. There was a user years ago that came to my place with an SD with a manual, and he absolutely loved it. I think the only challenge for him was the clutch pedal. I am not exactly sure what the issue was, but he did solve it.

Set the transmission in park with the park brake disengaged. Can you roll the car?

Sixto
98 E320s sedan and wagon

No, it is locked when in Park with no parking brake.
The trans output shaft spins freely in both directions in all other gears.


Jeff

I got my second ‘83 SD rom a forum member when the output shaft splines sheared. The yoke spun freely on the output shaft. That’s not your problem if it holds in park.

My ‘81 SD came with a torn flex plate. Someone mentioned pulling a transmission cooler line to/from the radiator to check for ATF flow with the engine running. It’ll fill a gallon jug in a few seconds so have someone start the engine then kill it on your command when you confirm healthy flow. Pour what comes out back into the transmission. If there isn’t more than a dribble, you might have lost the front pump or torque converter.

How long did it take to engage drive or reverse leading up to this failure?

The transmission has ports to which you can connect a pressure gauge. An ALDA banjo bolt works. That gets into the you know what you’re doing realm where I’m not qualified :)

Sixto
98 E320s sedan and wagon

How long did it take to engage drive or reverse leading up to this failure?

Now that you mention it, seems like there has been a bit of a lag lately before the gear would engage.
I will do the flow test with a transmission cooler line and report back.

Which transmission line should I disconnect for the test?

Thanks Jeff

I think it is the right (passenger), but don't quote me on it. Either way, you can put a length of hose (1/2"ID?) on the cooler fitting and the other end in the same container.

front pump test
 

Fired it up and tranny fluid came shooting out from the passenger side of the radiator towards the tranny.
I had two different gallon jugs with with hoses to catch the fluid.
So it looks like the front pump is good.
That transmission cooler line has an S curve in it. Not severely kinked.
I lost a belt not a couple of months back and it bent the cooler line metal coil.
I've driven it like that for over 1K miles without problems.

Jeff

If you do find out what the problem is, I would definitely like to know. That could maybe help me to fix the trans I talked about in post #3. It had the exact same issue you are having. No movement in any gear, but still had good flow from the cooler line.

damaged cooler line
 

I reattached the damaged cooler line, tried to straighten the coil, and took a photo.

Hopefully, some of the tranny experts here will chime in and we will figure this out.

Jeff

That is not too far out of the ordinary. They all should have a little curve in them. As long as it does not leak, it should be just fine.

A few words as
It goes for the transmission with no gears forward, if you have reverse its either the b2 piston or a broken band. If you have no gears - shifter linkage , band itself is broken , or other.i believe I've had all the above and each was a fix or went for a know n good replacement ,that requires some trust form the seller of the used trans.