Did my mechanic do it? Tranny gone??????

[mcgonza]

I have a 1999 MB ML430 200K miles. All was good until I turned a corner and the tranny went into limp mode. Got it to the nearest mechanic and he diagnosed it as the conductor plate. We wait on the the parts, he claimed he order two weeks earlier. During that time he said he would seal up the tranny and the plug so we could take it home because he needed the room in his shop (two blocks away). We got it home and notices a very steady leak coming from transmission. We refused to drive it back to his shop, well i wasn't going to because it wouldn't go into gear. However he came and got it. He fixed the conductor plate, new plug and harness. He did show us mild small metal shaving on the conductor plate, no chunks, just a little metallic color. Took it home and there was that leak AGAIN! He took it back to his shop and said the front end seals had blown due to the mileage and the pressure build up and having weak old seals. NOW, I'm extremely P.Oed because now that he has pulled the tranny to seal up everything, he's saying my tranny is bad!!! Said there is some sort of sleeve or something that broke causing all of this. I don't want to believe all this could be happening! Wouldn't he have determined my tranny was bad when this all started??????

[97 SL320]

Don't mistake someone not really knowing what they are doing for malice.

It sounds like they assumed the conductor plate was bad because it hit limp.Failed conductor plates are pretty common.

Other issues can cause limp besides the plate. There is a chance that the trans was making metal, this metal stuck to the speed sensors ( on the conductor plate ) causing the signal to be altered / falling into limp.

There isn't anything that they could have done externally with trans installed or through the pan to make the front seal leak. And, changing the conductor plate won't cause pressure to build up blowing the seals. You need to scan the transmission controller for codes before going farther.

So, it goes like this:

Trans is failing and making metal before anyone works on it.

Metal covers speed sensors / slippage while driving / control valves stick.

Trans goes into limp.

Shop changes conductor plate. ( Maybe due to codes or because it is a common failure point. )

Something in trans is still failing, front pump bushing / seal are affected / fluid leaks out.

[liquiddog]

Sounds like your mechanic actually cares... Could he have checked the oil pan for metal? 200k is a lot of miles. If this is your only problem you are a lucky dog!

[Elektri]

200k, time for a rebuilt transmission. It was the driver's fault (who put 200k on it!)

[MAVA]

Mcgonza,

Welcome to the forum, sorry for your problems. Nobody wants to have drive train problems..

Now, you did not say where it leaked as it can be four or five spots.

By the way, I rebuild these transmissions, and all the flavors of late 90's Mercedes transmissions have two vent holes-one on top of the front transmission tunnel-The other is on is just above the front shaft level.

Maybe the transmission was over filled? and maybe your tech does not have the 722.6(this is what you have) testing dipstick. Maybe the mechanic just measured the amount of oil that came out?

Since it went into limp mode, did your mechanic inspect the transmission computer? Very Very common for the transmission fluid to leak past the circular electrical connector and contaminate the transmission computer.. The fluid wicks-up on the wiring to the computer. Do let them sell you a new computer as the computer can be opened and clean with a paper towels and electrical contact cleaner. 99% of the times the transmission computer never fails(even with fluid contamination-it just needs to be cleaned work right).

The front seals blew? ahh... kinda not possible. First, their is only ONE front seal?

A)Overfilled possible leaking from the front vent or the top vent.

B) lack of oil, or running it on lack of oil will damage the main oil pump to grind down the pump and cause the bushing bearings to wear then the fluid leaks past the front seal because too much wooble...

Martin

[MAVA]

Have you gone MIA-Missing In Action?

[Rob Armstrong]

Hey guys. New member. Sorry if this isn't the correct place to post this but I searched for conductor plate and it brought me here.
I have a 97 e320 code is p0560 "low voltage"
Car is stuck in limp mode.
Power windows and stereo work while car is on but not running.
As soon as I start it and drive it all stops working. If I apply the brakes my radio will come on for a short period.
I have read that it could be my shifter wire harness had something spilled on it. So I removed it the other night and cleaned up the terminals on the right side. Small 2 pin plug. The rest looked in great shape so I hit em with some grease and re installed.
Then I had to look for a guy with the 30+ pin under hood data port as my friends new snap on scanner couldn't read all the codes without that plug.
When I got in the car this morning I was nervous because I live on a hwy and 40kph is not safe. Well it started to drive and shift like normal. Radio and windows worked and everything. I was so exited. Brought the car home. On my next trip out... Limp mode. Again.
So I found a guy with the under hood plug and went over to his house tonight.
Limping most of the way. Then I made a quick stop and when I fired her back up she drove fine over to buddy place.
He scanned it and he got the same p0560 code I got.
There goes $20 and a case of beer.
On the way home it drove great everything still working so I figured I would go for a bit of a cruise and enjoy it. Made it just around the corner from my house and boom limp mode again.
Any help is welcome and thanks for your time.
If this is in the wrong place or you think I will get a better response if I create my own thread just say the word.
Thanks again

[Hogweed]

exactly why i didn't pursue fixing my ml tranny....yet

Originally Posted by 97 SL320

Don't mistake someone not really knowing what they are doing for malice.

It sounds like they assumed the conductor plate was bad because it hit limp.Failed conductor plates are pretty common.

Other issues can cause limp besides the plate. There is a chance that the trans was making metal, this metal stuck to the speed sensors ( on the conductor plate ) causing the signal to be altered / falling into limp.

There isn't anything that they could have done externally with trans installed or through the pan to make the front seal leak. And, changing the conductor plate won't cause pressure to build up blowing the seals. You need to scan the transmission controller for codes before going farther.

So, it goes like this:

Trans is failing and making metal before anyone works on it.

Metal covers speed sensors / slippage while driving / control valves stick.

Trans goes into limp.

Shop changes conductor plate. ( Maybe due to codes or because it is a common failure point. )

Something in trans is still failing, front pump bushing / seal are affected / fluid leaks out.

[97 SL320]

Rob, you have a grounding point or wiring failing. ( due to windows / radio acting up )

Mercedes tends to place grounds on a few common bolts, start there and remove / clean.

Look for mouse nests / bite marks on wiring.

I have a 97 E320 parts car that exhibits really strange behavior when in trans limp. Left fog light turns on / high beam indicator on dash is on / a failure message on the dash ( Don't recall what it says. )

One time the symptoms went away and trans shifted just fine so I know my problem is car side and not trans side.

[Rob Armstrong]

Thanks for the advise.
I believe it's the shifter that's causing the issue.