82 380sl trans not engaging in any gear position

[dad380sl]

It has been several months since I completed the swapping of a 5.0 liter 117.961 Euro engine into my fathers 1982 380sl.
I drove the car about 4days ago and yesterday, I decided to take her for a drive but it would not engage in any gear. Nothing at all. No reverse or forward in any gear position the car just would not move. This seemed odd because I had just driven the car a few days ago. I was only able to check fuses and all linkage bushings were also replaced when I was doing the conversion. I'm just baffled at what this could be. during my search for a cause, many pointed to a failed pump, but i can't justify that the trans pump just decides to suddenly quit. Therefore I am thinking it could be something else.

[97 SL320]

These are more or less in order of testing / likely hood.

With the engine off, run the shifter back and forth then look under car for linkage movement.

With the rear wheels elevated, brake off, shifter in park, try to turn the drive shaft. Transmission output shaft flanges sometimes strip out due to wear. This happens a lot on older cars.

Was the fluid somewhere near the proper level when the car was driving? With the engine off and car sitting for a day or more, is the fluid level higher on the stick than when car was driving? Start engine, check level, if level went down, pump is turning. If level stays high, pump isn't turning.

There should be a pressure tap on the trans, you will need to check line pressure.

The ears on the torque converter that drive the pump can suddenly shear off due to fatigue. The above pressure test can determine this. Or removing a cooler line and looking for flow. Be sure to put both ends of what you have disconnected in a pan unless you know for sure what line fluid will be coming from.

Sometimes the line pressure regulator spring can break leading to very low pressure.

[dad380sl]

Originally Posted by 97 SL320

These are more or less in order of testing / likely hood.

With the engine off, run the shifter back and forth then look under car for linkage movement.

With the rear wheels elevated, brake off, shifter in park, try to turn the drive shaft. Transmission output shaft flanges sometimes strip out due to wear. This happens a lot on older cars.

Was the fluid somewhere near the proper level when the car was driving? With the engine off and car sitting for a day or more, is the fluid level higher on the stick than when car was driving? Start engine, check level, if level went down, pump is turning. If level stays high, pump isn't turning.

There should be a pressure tap on the trans, you will need to check line pressure.

The ears on the torque converter that drive the pump can suddenly shear off due to fatigue. The above pressure test can determine this. Or removing a cooler line and looking for flow. Be sure to put both ends of what you have disconnected in a pan unless you know for sure what line fluid will be coming from.

Sometimes the line pressure regulator spring can break leading to very low pressure.

linkage operates as it should. fluid level is ok, fuse is ok. i have to check the line pressure. It is just odd because I just drove this car 4 days ago. I drove for around 6 miles and came back home parked exactly where it was before and it sat for only 2 days. I dont undersatnd how the transmission could just stop working.

[97 SL320]

Originally Posted by dad380sl

linkage operates as it should.

Did you check the linkage for movement _after_ the problem occurred?

Originally Posted by dad380sl

fluid level is ok,

Did you follow my exact fluid checking instructions? What levels did you see in both checks?

Originally Posted by dad380sl

fuse is ok.

What ever fuse you checked, it won't keep trans from driving.

Originally Posted by dad380sl

i have to check the line pressure. It is just odd because I just drove this car 4 days ago. I drove for around 6 miles and came back home parked exactly where it was before and it sat for only 2 days. I dont undersatnd how the transmission could just stop working.

Did you check the drive shaft per my instructions?

[dad380sl]

Originally Posted by 97 SL320

Did you check the linkage for movement _after_ the problem occurred?



Did you follow my exact fluid checking instructions? What levels did you see in both checks?



What ever fuse you checked, it won't keep trans from driving.



Did you check the drive shaft per my instructions?

i checked everything as per your instructions everything with the exception of checking line pressure.
everything checks out, the fluid level seems to stay around the same level. It all points to the pump. but I cant understand how I drove home the other day and parked it, and now it doesnt want move! just bizzarre.

[dad380sl]

where can I find instructions on changing the transmission pump if I find that it is the culprit and how difficult is the task?

[97 SL320]

Originally Posted by dad380sl

where can I find instructions on changing the transmission pump if I find that it is the culprit and how difficult is the task?

One possibility of sudden loss of drive was addressed in Post 2 paragraph 6.

Put a pressure gauge on line pressure tap. If you don't have a gauge, pull the cooler lines and check for flow. No flow = sheared pump lugs.

[dad380sl]

Originally Posted by 97 SL320

One possibility of sudden loss of drive was addressed in Post 2 paragraph 6.

Put a pressure gauge on line pressure tap. If you don't have a gauge, pull the cooler lines and check for flow. No flow = sheared pump lugs.

Thank you for that. I wanted to know if the pump is something I can change myself.

[97 SL320]

Originally Posted by dad380sl

Thank you for that. I wanted to know if the pump is something I can change myself.

I don't know what your abilities are, usually when the question is formed as such, I say no. ( When the question is formed, "what special tools, things should I look out for when changing the front pump?" I tend to say yes. )

Do a search for a poster named Stretch, there is pretty a intensive trans teardown with pictures that should be in the Tech section.

The front pump on this unit might need a alignment tool to center the pump body halves, that should be addressed in the tech write up.