Something broken? No power from engine to wheels - PeachParts Mercedes-Benz Forum

ROLLGUY · #1 07-02-2011, 12:36 AM

1985 300D (belonging to a non-computer savvy friend of mine) all of a sudden no power to the wheels in any gear. We know the driveshaft is intact, as PARK works. I once had a drive hub break off of the torque converter on an AMC I have, and it gave the same symptoms. Has anyone else had a similar problem with their 'Benz?
Is it possible that the flex plate broke without warning or any sound? Could their be something inside the trans that could have broke? Any experiences or help would be appreciated. Thanks, Rich

tbomachines · #2 07-02-2011, 12:44 AM

Only answer is to investigate yourself. Is the driveshaft intact? Flex discs connected? Does reverse work?

jt20 · #3 07-02-2011, 01:02 AM

Quote:

Originally Posted by ROLLGUY

Is it possible that the flex plate broke without warning or any sound? Could their be something inside the trans that could have broke? Any experiences or help would be appreciated. Thanks, Rich

Flex plate - maybe. It would have to be that all six bolts sheared / fell out for there to be no sound.

.,..it makes the most sense to me since my limited understanding of the trans is that the common failures usually allow motion in some direction (reverse or at least one gear forward).

Has he tried ALL positions, ruling out a fault in the shifter and linkage?

tbomachines · #4 07-02-2011, 02:13 AM

Quote:

Originally Posted by jt20

Flex plate - maybe. It would have to be that all six bolts sheared / fell out for there to be no sound.

.,..it makes the most sense to me since my limited understanding of the trans is that the common failures usually allow motion in some direction (reverse or at least one gear forward).

Has he tried ALL positions, ruling out a fault in the shifter and linkage?

More likely a B2 failure, if reverse works. Flex PLATE (not disc as most refer to) is certainly possible, but at that point so is the transmission pump, driveshaft, and torque converter.

layback40 · #5 07-02-2011, 02:45 AM

Quote:

Originally Posted by tbomachines

More likely a B2 failure, if reverse works. Flex PLATE (not disc as most refer to) is certainly possible, but at that point so is the transmission pump, driveshaft, and torque converter.

Some of the older trans had a common problem with the failure of the drive of the pump on the end of the TC.

kerry · #6 07-02-2011, 11:13 AM

Does it have reverse?

jt20 · #7 07-02-2011, 12:24 PM

Quote:

Originally Posted by tbomachines

More likely a B2 failure, if reverse works. Flex PLATE (not disc as most refer to) is certainly possible, but at that point so is the transmission pump, driveshaft, and torque converter.

He said "no power to wheels, but park works". To me, that means zero motion in any direction.

And I am quite familiar with the flex PLATE. There are 6 bolts holding it onto the torque CONVERTER.

ROLLGUY · #8 07-02-2011, 08:02 PM

Quote:

Originally Posted by tbomachines

Only answer is to investigate yourself. Is the driveshaft intact? Flex discs connected? Does reverse work?

As stated above, driveshaft is connected, as park holds the car from moving.

ROLLGUY · #9 07-02-2011, 08:05 PM

Quote:

Originally Posted by layback40

Some of the older trans had a common problem with the failure of the drive of the pump on the end of the TC.

Being an '85, would that be one of the "older" ones?

ROLLGUY · #10 07-02-2011, 08:08 PM

Quote:

Originally Posted by jt20

He said "no power to wheels, but park works". To me, that means zero motion in any direction.

And I am quite familiar with the flex PLATE. There are 6 bolts holding it onto the torque CONVERTER.

Have not been able to get under it to investigate, but a broken flex plate makes the most sense. I was just wondering if it was a common problem, or if it is broken, would it just be a random failure?

layback40 · #11 07-02-2011, 11:05 PM

Quote:

Originally Posted by ROLLGUY

Being an '85, would that be one of the "older" ones?

No its not one of the older ones but it still can happen. The fact that you dont have any scraping noise makes a failed flex plate unlikely. If the 2 drive pieces on the TC have broken off, there will be no noise & no drive. The B2 failure can be investigated with the trans in place. I dont know if you loose reverse with a B2 failure though. If its not the B2 then the trans needs to come out.

Chas H · #12 07-02-2011, 11:16 PM

Get your friend to move the shift lever out of park and then try to push/move the car by hand. If it won't move the shift linkage is likely the problem, if it does move your friend car has a major problem. I doubt the flex plate or its attachments to the engine or TC is broken if nothing was heard.

Jeremy5848 · #13 07-02-2011, 11:25 PM

What about "no transmission fluid?" Granted, that should be noticed on the ground under the car but it fits the symptoms. If the car doesn't move in any gear, I wonder how they knew "Park" worked? Tried to push or roll the car?

As to the "older" transmissions, the 1985 300D-T (W123.133, OM617.952) got the 722.416 transmission if it was a California version, a 722.315 if it was Federal. Both had been in use for several years at that point and continued to be used (on diesels, at least) until the 722.6 was introduced in 1997. Both were and are reliable boxes but anything can break. Some kind of internal TC failure sounds reasonable to me.

layback40 · #14 07-02-2011, 11:32 PM

Quote:

Originally Posted by Jeremy5848

What about "no transmission fluid?" Granted, that should be noticed on the ground under the car but it fits the symptoms. If the car doesn't move in any gear, I wonder how they knew "Park" worked? Tried to push or roll the car?

As to the "older" transmissions, the 1985 300D-T (W123.133, OM617.952) got the 722.416 transmission if it was a California version, a 722.315 if it was Federal. Both had been in use for several years at that point and continued to be used (on diesels, at least) until the 722.6 was introduced in 1997. Both were and are reliable boxes but anything can break. Some kind of internal TC failure sounds reasonable to me.

Internal TC failures normally make horrible noises. Often cause a TC lock up.

Jeremy5848 · #15 07-02-2011, 11:45 PM

Something in the transmission, then? Seems to me all of the transmission failures I've read about come on gradually, with the loss of one gear initially, or slipping as it shifts, gradually getting worse. This sudden failure to move is puzzling absent any report by the OP of some kind of accident or other event.