722.6 Transmission Pan Torque Value and Sequence

[Mino Erhan]

Hi All,
Changed the fluid on both my ML and S recently with MB fluid.
New MB pan gasket and MB Filter was installed. Level is checked with OE Tool using MB fluid.
Pan was tightened to 8Nm.

The book calls for 8 Nm torque but no sequence is called out. There are only 6 bolts.
No fluid leak on the S, and a constant little leak on the ML.
Both sealing surfaces were checked and cleaned.
Q: Is there a specific tightening sequence? I didn't see one in the manual.
Q: Anybody ever had to replace the pan, due to some warpage? Its never been hit or anything.
I don't want to waste the fluid if at all possible..
Appreciate the input as always.

[RAYMOND485]

1984 300d Turbo 147k
Replace The Trans Pan Order This Site, And New Gasket Its Warp,bent, May Try To Increase Torque

[TMAllison]

Different animal than a 722.3.

First I'd drain the pan fluid into a clean container so it can be reused, and then loosen it enough to see that the gasket is seated uniformly all the way around the lip of the pan with no nicks on the seal or debris present. Then I'd try a new gasket before going to a new pan. It's a very reliable system/seal.

The plastic hold downs bottom out. Unless you shattered one I don't see how you can warp the pan using them.

[Carson357]

it is possible the data plug electrical connector is leaking, i usually replace those at service to avoid issues, mercedes calls it a pilot bushing, is located passenger side front of transmission

[nhdoc]

The bolt torque does not determine sealing capability on these pans and I don't think the order in which they are installed matters either. They are ingenious in that the bolt basically bottoms out in a metal clamp/spacer to apply clamping pressure to the edge of the pan but you really can't over or undertighten them if you are even close.

If the leak is from the gasket it was either defective or you had some crud under the clamping piece which the bolt goes through that acts as the spacer and clamps the pan in place. I can't swear by it but I thought there were more than 6 bolts...8 perhaps on the 722.6. Each one goes through a metal "clamp" that holds the pan. These pans are pretty beefy so I doubt it is the pan itself that has warped...I am guessing user error in the install...try again.

[Mino Erhan]

Thanks guys,
I have re installed and cleaned, and re torqued the pan, and its still leaking from the passenger side, enough to bother me.
I hope its not "operator error", as I have done this without any trouble on many other cars, including my other MB's which have the same 722.6 transmission.

But, after more careful examination, I saw some wetness around the connector. I took the connector off and I saw an Oring, which looked like it took a set, I replaced it. When I look at the manual, it shows the guide bushing attached via bolt to the transmission. It also shows another Oring on the guide bushing.
What kind of bolt does this guide bushing have? I cannot see it, due to the angle its mounted. Of I remove the guide bushing do the wires come out also?
Any input is appreciated as always....

[Carson357]

the part you need is 203-540-02-53 #115 in picture below, it comes complete with the inner o-rings

[Mino Erhan]

Thanks nhdoc.
You are correct, the torque value doesn't matter as the bolt does bottom out on the clamp, if so the sequence doesn't matter either. I agree. There is something else wrong. I will look again and report more.
Thanks Carson357
The part you show is the connector? I am a bit confused. My connector has only 1 Oring which I replaced already. The other O ring seems to be on the guide bushing, which that part is attached to the transmission. My question is, how do I take the guide bushing out to replace that Oring?
By the way, how can obtain the parts manual (fiche) like you have?
I will investigate some more.....
Thanks all..

[nhdoc]

If it is leaking from the connector you should buy the updated part from M-B and replace it. These were notorious for leaks but since you said it only started leaking after you dropped the pan I assumed you had a leak at the pan gasket. Just visit your local dealer and pick up the updated connector, they should all stock them.

You can sign up for the EPC online for free:

http://epc.startekinfo.com/epc/

You do need to give them a CC but the charge is $0.

[Mino Erhan]

Thanks Marty,
Is it difficult to change the connector? I guess they replaced the 2 piece (connector and guide bushing) with a single piece one?

You know,... I saw this site before, but didn't subscribe. I will now. Thanks again.
Gotta go to a meeting now. Can you believe a meeting on a sunday?

[Carson357]

Originally Posted by Mino Erhan

Thanks Marty,
Is it difficult to change the connector? I guess they replaced the 2 piece (connector and guide bushing) with a single piece one?

You know,... I saw this site before, but didn't subscribe. I will now. Thanks again.
Gotta go to a meeting now. Can you believe a meeting on a sunday?

it is not difficult to do there are two parts, the actual outer plug where the wires connect to and the inner receptical, the inner part is what seals the fluid in the transmission, when you release the electrical part and look inside you will see a retaining bolt, the head is 7mm, loosen the 7mm and pull out the part, it will help if you drain some fluid from the transmission so you can be sure to keep the area clean, put some new atf on the o-rings and insert it, pay attention to how it is removed, as it will only go in one way, if you look closely you will see aligning tabs close to the 2 and 4 o'clock positions on the plug and in side where it attaches, when it goes in snug the 7mm lightly, if you go too tight it may cause the other end to break loose and spin in the plastic housing, if this happens the entire valve body will have to be removed and the conductor plate replaced.