How do I know if the torque converter is good? It's not leaking. 85 300SD

__________________
85 300 SD ~ 115K
82 500 SEC Euro ??K
78 450SL 164K

It will turn the splined input shaft going into the trans=motion. But the test for TC operation requires hooking up a gauge to a TC pressure tap to perform a line pressure test with. The tap is a small pipe plug you can remove to thread a pressure gauge and long hose to observe pressure readings while driving/operating. Most line pressures do not exceed 80-100 psi Your other post also caused me to think that the stator and turbine assembly (both serviced by TC replacement) may have come apart. You would therefore get fluid pressure from the pump b/c the TC collar turns it (the part you checked to see if it was sheared). But the TC is the fluid coupling for forward or rearward momentum. If it were mine, I would see about getting a good used TC (someone from here or even at a pick n pull) throw it in and see what happens, since its already out. Worse case scenario, throw a whole used trans in, if need be - TC and all.

__________________
Thanks,
Mark in NC

"Spark plugs?...We don't need no stinking spark plugs!"
1985 300SD "Der Silberne Schlitten" 420,000 mi


Wish these were diesel:
2003 Ford Club Wagon 130,000 mi

To test Torque-Converter you'll need the engine in Good State of Tune and an accurate Rev Counter attached to engine.

There is a specification in WSM thats called TQ Stall Speed.

With Brakes firmly applied, You run the engine at Full Throttle for no more time than necessary to read the Maximum speed of the engine, on an Accurate Rev Counter--The Car rev-counter may not be accurate enough.....

--This engine-speed should equal the TQ Stall-Speed quoted for your car/trans/engine combo....

Not sure what the above post test is measuring, but it aint the effectiveness of the TQ!

--Line pressure affects the operation of the Transmission.....
--Not so much the Converter--Providing the Line-pressure is actually There that is!

__________________
http://i190.photobucket.com/albums/z...0TDnoplate.jpg

Alastair AKA H.C.II South Wales, U.K. based member

W123, 1985 300TD Wagon, 256K,
-Most recent M.B. purchase, Cost-a-plenty, Gulps BioDiesel extravagantly, and I love it like an old dog.

W114, 1975 280E Custard Yellow,
-Great above decks needs chassis welding--Really will do it this year....

Sorry Alastair - stupid questions:

1) do you select drive or keep it at a lower gear?
2) how do you know when the torque converter has "stalled"? Or does the torque converter just act like a rev limiter (I understand that the injector pump limits revs too)

Sorry for the dumb questions I'm still learning!

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I know mine works because it jumps right up to the stall speed when I floor it off the line.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)

mack0415 So if I get another torq converter would I have to install the trans to see if that was the problem or could I tell on the bench? Thanks

__________________
85 300 SD ~ 115K
82 500 SEC Euro ??K
78 450SL 164K

It doesn't matter what gear, provided the car isn't moving. The "stall" is where the engine will develop no more RPM with the wheels stopped.

__________________

Gone to the dark side

- Jeff

Just remember : only a few seconds as it heats up REALLY fast doing this and you can screw things up royally in 30 seconds .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

The stall speed test will only confirm that the engine is making its rated power and that the stator clutch is not slipping. It will not troubleshoot a locked stator.

If the stator clutch is slipping, the engine will not make stall speed, and the car will be very sluggish on take-off.

If the clutch is locked up and not over-running when it should, the car will accelerate OK, but you will have to keep your foot in it just to maintain speed, like driving with the brakes on.

Rebuilders have a way to test them, but for us, installation may be the only way.

__________________
Thanks,
Mark in NC

"Spark plugs?...We don't need no stinking spark plugs!"
1985 300SD "Der Silberne Schlitten" 420,000 mi


Wish these were diesel:
2003 Ford Club Wagon 130,000 mi

Sorry Alastair. I am also responding to another string JimandSuzy started: http://www.peachparts.com/shopforum/showthread.php?t=287812

The trans will not move in forward or reverse gears, the fluid is clean and red, and no metal in the pan. The trans has already been removed, if my understanding is correct. Aside from checking basics, like shifter linkage, a
line pressure test would have been telling of the overall hydraulic circuit condition in all gears while it was still in the car. He stated the TC ears are not sheared off, so the pump is being turned (he also stated that he pulled the cooler lines and started it up - of course fluid was being pumped out). How many of you have seen a TC come apart internally? I have seen a few, but not MB - but it is the same theory. If there is a massive internal hydraulic circuit leak, line pressure would tank and cause inadequate clutch piston application. What do you all think?

__________________
Thanks,
Mark in NC

"Spark plugs?...We don't need no stinking spark plugs!"
1985 300SD "Der Silberne Schlitten" 420,000 mi


Wish these were diesel:
2003 Ford Club Wagon 130,000 mi

I decided that rather than break something I can't fix in the trans I took the trans and TC to a local rebuilder. They're going to look at it one day next week. Will post results. Thanks

__________________
85 300 SD ~ 115K
82 500 SEC Euro ??K
78 450SL 164K

Good news - trans shop said the torq converter is broken internally. Bad news - they say a rebuilt is $500 over the counter. I'm going to search for a used one. Any one know what other models use the same converter as the 85 300SD? Do the older 300SDs use the same one, how about V8s? Thanks

__________________
85 300 SD ~ 115K
82 500 SEC Euro ??K
78 450SL 164K

I'd go with another 617 TC, not sure that the stall speed will be different between 123/126 bodies but should be the same on all OM617-W126 cars (my guess).. I'd be VERY surprised to find that the gasoline engine TCs are the same.

__________________

Gone to the dark side

- Jeff

You can buy a rebuilt TC for around $200. Make sure to get your core back.