Something broken? No power from engine to wheels - Page 2 - PeachParts Mercedes-Benz Forum

ROLLGUY · #16 07-03-2011, 12:03 AM

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?

I had just worked on the car an hour earlier (replaced belts, rad hose, oil cooler hoses, changed oil). He went out to do errands, and after the second one, it would not reverse out of the parking space. The first thing he checked was the trans fluid level, and he said it was low (about a quart and a half). He had a friend bring some ATF, but that did not fix the problem. They pushed it back to his place, and parked it. He called me wanting to know if I had any ideas (I thought he was blaming it on me or something I did). He was going to put it up on stands and have a look at the flex plate mounting through the oblong hole in front of the flywheel, but has not told me yet what he found (if anything). If it is the flex plate, the TC bolts will not line up with the holes in the flywheel, and would be easy to see if that is the problem. If it is not obvious, the trans may need to come out.

ROLLGUY · #17 07-03-2011, 12:08 AM

Quote:

Originally Posted by Jeremy5848

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.

A friend of mine bought a car that had been rear ended, and he found that the flex plate had sheared off just around the outside of the mounting bolts. My friends car was working perfectly one moment before parking, and then no movement in any gear the next.

Stretch · #18 07-03-2011, 02:23 AM

There doesn't seem to be a fault section in the 722.3 manual but in the 722.1 ATSG manual is says this for a no drive in any gear situation:-

1) Primary pump failure
2) Stuck selector sleeve:- The test for this is to measure the main pressure and see if it increases with engine speeds.

Before you take out the transmission - which seems to be the way you are going - see if you can measure the pressures as per the ATSG manual.

kerry · #19 07-03-2011, 09:15 AM

Simple test is to pull one of the cooler lines and see if fluid is being pumped or not.

ROLLGUY · #20 07-03-2011, 09:39 AM

Quote:

Originally Posted by kerry

Simple test is to pull one of the cooler lines and see if fluid is being pumped or not.

Great idea. I will try this first. Thanks, Rich

ROLLGUY · #21 07-09-2011, 12:05 PM

Quote:

Originally Posted by kerry

Simple test is to pull one of the cooler lines and see if fluid is being pumped or not.

UPDATE: I put the car on stands, and loosened the trans cooler line on the driver side (50% chance of getting the output side, I chose correctly) and had my friend start the engine. First a bit of air came out, and then a steady stream of fluid. I now knew that the pump is working. I then drained the pan, and torque converter overnight. The next day we decided to put it all back together, thinking it might have been a clogged filter, or just low on fluid (only drained out about 7 qts). We put in about 9 qts in order to get a reading on the stick, and added another qt. Started the car, and still no movement. When the pan was off, I had my friend move the gear selector back and forth. I could see a plastic part moving in and out of a hole (gear selector valve?) in the valve body. Could that piece be broken inside the valve body? I know enough about the inside of a trans to be dangerous, so I did not remove anything to inspect for broken parts. I have a friend with a dead trans that I can take apart and see what it looks like inside. If there is a simple test I could do, I would do it before pulling the trans. I do not want to pull the trans, only to find out something simple to fix was broken inside. My friend may just decide to junk the car instead of fixing it. I would get first dibs on it though. I would rather see it back on the road if possible, but he does not want to put a lot of $ into it......Rich

chasinthesun · #22 07-10-2011, 10:48 AM

Ive had the B2 piston experience ,lost all forward gears but still had reverse ,when it came time to put it on the trailer it was a savior.If there was no lag in performance before the problem I would give it to a small part in the tranny letting go.

ROLLGUY · #23 07-10-2011, 04:05 PM

Quote:

Originally Posted by chasinthesun

If there was no lag in performance before the problem I would give it to a small part in the tranny letting go.

It just quit all at once. He parked it after driving a half hour or so, and went to back out of the parking space, and nothing. What part could cause this?