Trans failure question
 

Ok. So I'm driving home and the car starts to feel a little sluggish. I have a hill I drive up to get to my driveway and as I'm coming up it suddenly I loose drive AND reverse. No noise, actually killed the engine. Upon restarting, nothing.

Checked the trans level and it over full.., it was spot on 2 weeks ago and I have not added any.

I have to car up on jacks, If I put the car into drive, I can see the rear wheels sort of pulse a little like it's trying.

I pulled off the trans cooler line, drivers side and no fluid...

and restarted the car, no fluid came out.

I can put the car into gear and from turning or not turning the drive shaft feel that it's engaging.

I'm personally guessing the pump blew? if so, whats the steps to fix?

BTW, here are the trans numbers...

123 20 78 01 722.315 02 593477

it's also possible the ears that drive the pump sheared... or even the flexplate that connects the flywheel to the TC has broken... but I think this would make some noise...

Which car? I had an 81 SD that kinda sorta did that. Flex plate tore apart. See if you can turn the TC independently of the ring gear. If not, mark the ring gear and TC then run the engine for a moment to see if they slip.

Sixto
87 300D

In my 85 300D that I just put the new engine in.

... this is a classic sign of someone who did not install the TC into the transmission pump properly...
can you describe EXACTLY what you did regarding the TC and the transmission during your engine install?

hmm... well, off the top of my head, I pulled the trans off the bad engine unbolting it from the flywheel, then lined it up and put it back on the new engine and bolted it back up.... I don't remember actually taking out the torque converter.

Plus it been working fine for the last 7 thousand miles... I'm trying to research it now in the do it yourself section to see if I can come up with anything, but it's looking like I'll have to pull it out again.

"Unbolting it from the flywheel?" The flywheel is bolted to the crank, the trans is bolted to the block. It sounds like you kept the TC attached to the good engine. That's a problem right there.

Sixto
87 300D

No the new engine didn't have a TC.

I unbolted TC from the flywheel, Then the trans from the block, Then separated them. The TC stayed in the trans. Then I pushed it over to the new engine and bolted it all back together.

Oh, I see. So the TC never came off the trans. Maybe it slid forward enough during handling to disengage from the pump tangs. You'll know soon enough :/

Sixto
87 300D

ya.. I see no other real option put to pull it.

Now the dilemma...

Since I'm going to the work of pulling the engine and trans again, should I just go ahead and pull the engine and trans out of one of my keepers and put that new engine in one of them instead. I think in the long run the TD is going to be my keeper. It has a LOT of miles on it, around 360k, but runs clean no blow by new timing chain, ip tuned etc... runs really smooth... Or my CD, with unknown miles, showing 200k, broken odometer, I'm sure it's due for a timing chain, needs a couple GP.s yada yada...

My wife wants to see the engine go into the TD. Since of course, It's the one I'm in the process of redoing. Doing this I'm still going to be one trans short since this one is most likely shot from what I'm guessing.

So, that may relinquish this car to parts car status after all.

And if that's the case, I could really go ahead and leave it alone for now, let the new engine sit in it as a known good spare, and part out the rest of the car.

And there are parts I could use off it, like the windshield for the TD, the set of new tires could also go on the TD, the headlights to the TD...

That's kind of what I'm leaning towards. The pump doesn't seem to be functioning, if I can pull the drivers trans cooler line and run the car with the trans in gear and not see any fluid come out. plus the trans level showing the system as being way overfull, no fluid really even came out when I disconnected that line, it's like it's all backing up...

The pump won't turn if the TC isn't turning, which is what happened to me. Trans and TC were fine after I installed a new flexplate.

Sixto
300D

Flex and TC are turning. I can look up and see them turning. Trans holds gear, neutral is neutral putting it into gear stops me from being able to turn the drive shaft etc... everything seems to point to the pump...

Like someone said already, you will know as soon as you pull the transmission. It's somewhere in that area- pump, tc or flexplate. You don't need to pull the engine.

Easier to pull engine and trans as one unit. I know how hard it was to get the trans lined up to the engine with them both sitting on the ground in front of the car, I can only imagine the pita it would be with the engine in the car.

Slept on it and I'm done with this car and going to part it out. I'll keep the engine as a spare for my TD down the road, going to also use the windshield, front lights and tires for the TD, the aux water pump and the mono valve.

The perfect wood will go into the CD to sell it.

The cars worth more to me in it's sum of parts at this point.

So anyone that needs and entire blue mb tex interior thats literally in like new shape speak up. I even have a new molded blue plastic dash cover for it, One of the ones that looks almost stock when installed.

btw, could you link me to a how too so I don't make the mistake again:? The downloaded manual I have for the w123 is missing the entire section the the automatic transmissions.

I'm about to pull the engine and trans out, only the engine mounts are left holding it down, then I will separate them and see what I can tell. The trans fluid was totally clean, nothing spelled funny. will know more soon...

Engines and trans are out and undercover till tomorrow. Maybe... There is a call of rain moving in. Man I'm getting fast at pulling these. The actually total amount of time it took this time was about 2 hours. would have been faster with a helper.

None of the manual sets include the transmission, as far as I know. Mercedes has always made it extremely difficult to obtain their transmission manuals.

I would also like clear instructions on what to do. I may have to transplant a tranny in the spring, from my coupe into my TD, and (seeing as I already had a shop ruin a transmission doing the same thing on two of my cars, 10 years ago) I would like to do it right.

The transmission chapters are in the German FSM, but not in the US FSM. Strange, because most of the automatic transmissions are in the US.

Anyway, removal and inspection of the oil pump goes like this:

Inspect the oil pump.
Pull the TC from the transmission. Affix some metal strips to the TC so you can handle it better.

http://i185.photobucket.com/albums/x...119_hilv04.jpg

Preferably put the transmission upright to pull the TC

http://i185.photobucket.com/albums/x...119_hilv05.jpg

Now you see the oil pump housing

http://i185.photobucket.com/albums/x...119_hilv07.jpg

Remove the bolts, but two bolts in the two unused holes and pull the oil pump housing out of the transmission

Now you can see the oil pump housing:

http://i185.photobucket.com/albums/x...119_hilv08.jpg

And the transmission:

http://i185.photobucket.com/albums/x...119_hilv09.jpg

The old gasket can be removed, that will take time.
Remove the two teflon rings in the grooves. They are not closed, but open, so you can take them off. The two white rings are the teflon rings, old ones are black.

http://i185.photobucket.com/albums/x...124_hilv19.jpg

Here is an old teflon ring.

http://i185.photobucket.com/albums/x...124_hilv18.jpg

The teflon rings can be renewed, install with a bit of grease. The two ends have to be together, bend carefully if not.

Push down the disc which holds the springs and remove the locking ring which lays in a groove. Here you can see the locking ring already from the groove:

http://i185.photobucket.com/albums/x...124_hilv16.jpg

Remove ring, disc and springs.

http://i185.photobucket.com/albums/x...119_hilv14.jpg

Remove the thing with the tabs

http://i185.photobucket.com/albums/x...119_hilv15.jpg

And remove the bolts for the oil pump. You might need the bolts to push the oil pump out of its housing and then you can see this:

http://i185.photobucket.com/albums/x...119_hilv16.jpg

Remove the plate and then you can see the gear wheels of the oil pump:

http://i185.photobucket.com/albums/x...119_hilv17.jpg

These wheels pump the oil. The ring wheel must not have play and the teeth of both wheels should not be damaged. The tabs on the inner wheel must still be there. The TC shaft engages those tabs to drive the oil pump.
When put together, the wheels must be well oiled with ATF.
Inspect the bearing of the oil pump, it must not be damaged:

http://i185.photobucket.com/albums/x...0120_hilv4.jpg

You can put in a new seal:

http://i185.photobucket.com/albums/x...0121_hilv1.jpg

and a new rubber ring for the oil pump:

http://i185.photobucket.com/albums/x...124_hilv05.jpg

http://i185.photobucket.com/albums/x...124_hilv06.jpg

The thing with the tabs has two rubber rings, inner and outer which can be replaced:

http://i185.photobucket.com/albums/x...124_hilv12.jpg

Getting the thing in again is a bit tricky, it must be done straight, and the rubber points forward, so you might have to use something to push the rubber in. Use ATF to lubricate.

http://i185.photobucket.com/albums/x...124_hilv14.jpg

The oil pump bolts require 20 Nm when you put it back together again:

http://i185.photobucket.com/albums/x...124_hilv11.jpg

The transmission after the removal of the old gasket.

http://i185.photobucket.com/albums/x...0125_hilv1.jpg

And the new gasket for the oil pump. All the holes have to line up and there is only one correct way. Be careful not to damaged the bearing or the seal when putting back the oil pump.

http://i185.photobucket.com/albums/x...0125_hilv2.jpg

Torque the bolts to 13 Nm

http://i185.photobucket.com/albums/x...124_hilv24.jpg

The TC can be installed, best with a transmission in the upright position. Turn it is bit until the tabs of the oil pump are engaged. Turning the TC must feel different (heavier). Be careful not to damaged the bearing or the seal.

Well, I now know why the transmission failed....

First off I now believe this transmission has been rebuilt at one time.

See the blue markings like someones been in there? That plus the fact that the plastic "bolt" the retains the torque converter was gone...

http://www.peachparts.com/shopforum/...2&d=1327861744

Now onto the issue...

Notice how there are no tabs left for the torque converter...

http://www.peachparts.com/shopforum/...3&d=1327861771

See how this is separated?

http://www.peachparts.com/shopforum/...4&d=1327861793

So, it looks like Vstech was correct on me not seating the torque converter all the way during the reinstall... I need a new Pump.

Just to clarify:

1. Proper seating is a matter of turning the torque converter while you push, or pushing down as far as you can then turning?

2. When I do my trans swap from the Coupe to the TD, I need to double check that I haven't pulled the torque a bit loose from the pump in the process?

Many thanks Govert for the excellent writeup and pics.

I'm not sure what you are refering to in the pic " See how this is separated? "

The splined shaft is called a stator shaft and is supposed to be seperate from the input shaft.

The surest way to tell if the converter is seated is if it still moves front and back when the trans is bolted to the engine. ( this is before the flex plate to torque converter bolts are installed )

Also, if the pilot in the rear of the crank is very rusty, the converter will be forced into the pump causing the damage you have.

1) To seat it properly, you'll need to push the torque converter in at the same time as when you turn it. It's best that you turn it clockwise and push at the same time at least a dozen times to ensure it gets seated properly.

2) Pulling the trans will probably disturb the torque converter. Once pulled, you'll need to turn it and push to make sure it is reseated. But I highly recommend that once the tranny is down, you get a new front seal. This would require removal the torque converter anyways.




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Wonderful iinformation
 

To all the ones who posted in this link ty,, I know that I will have to open my transmission some day ,and I feel better about it because of the talented information that is posted here,, thank you !!! I bought a spare to work on to practice,, it's a 722.317 the one in my car is a 722321. only the speedo thing is different, the rest of the internals may be the same ,, Cheers

Also, keep in mind I put over 6 thousand miles on the car BEFORE this happened. So it was by no means a sudden failure after putting the engine trans back in. The transmission actually shifted and worked wonderfully right up to the point it failed. I'll get a new pump from Vstech, I believe I'm going to have to flush the Torque converter, replace all the filters etc in the trans since that metal had to go someplace... There was a very fine sand of it on the converter. HAve not dropped the pan itself yet.

When it failed it failed hard. Meaning I was coming up my hill, the car seemed underpowered for a second. I let up on the gas, shifted to neutral and back to drive (I was doing maybe 5 miles an hour) the car lurched and it killed the engine. Started right back up and had nothing as far as gears at that point. No noise, no grinding nothing.

I just had a look at my 300cd with the same trans failure and was able to pull a frt trans cooler line to check for fluid pressure coming out of the line when started ,a big yes on the pump working.Now the question is could my problem be something simple ?