I have just started a 722.6 transmission rebuild out of a 2006 Sprinter. I have this posted over at sprinter-source.com but wanted to get the input of people on this forum also.

Alright well...I pulled it apart. Here are my pictures.

Here is the oil pump:
http://drive.google.com/uc?export=view&id=12H-6fJc-pOjF-Cx9PU2kAB8LHHFjNleYag

Here is the bell housing bearing surface (oil pump side). It is gouged.
http://drive.google.com/uc?export=view&id=1KqT-zaxie-YPIXIr2-nMNU4gINkyEgOOMg

B1 Clutch Outer Housing. There is some rough edges but relatively smooth:
http://drive.google.com/uc?export=view&id=1TMr9dAlI9VgmtafHeHCcq2lT5R-81g26fQ

B1 Clutch:
http://drive.google.com/uc?export=view&id=1NWwK8wujFsHeR7a_UkearhsHY2Gm1NrIwQ

F1 Sprag. This guy isn't working correctly and needs to be replaced:
http://drive.google.com/uc?export=view&id=1NL3HRjEy-VCDTOEc0N-vO4fkpvtK8I4FSw

K1 Clutch:
http://drive.google.com/uc?export=view&id=1EICy-oz0OUUQmbBr3PvGWE1ODVRZj61uTg

K1 Clutch Housing Outer. Notice the grooves from the clutches:
http://drive.google.com/uc?export=view&id=1GWn7Hy-nIDo6hcWuWd_f82bpriL1LjF2vw

K1 Clutch Inner. Also notice the grooves from the clutches:
https://drive.google.com/file/d/1oKpu5biGLaHu_jqn0pkBiglpYN4oRIpcEA/view?usp=sharing

K2 Clutch:
http://drive.google.com/uc?export=view&id=1i_bfgyrsb2z_w1oLVGSwR6r64G-Rme3q-Q

K2 Clutch Outer Housing:
http://drive.google.com/uc?export=view&id=1YLAP93XvicafH-ES3o2EBeW2mOgHE-Tt8Q

K2, B3, and B2 Clutch Inner. Notice the significant gouging where the clutches contact on all three of these clutches:
http://drive.google.com/uc?export=view&id=1nXd-KA1YOzSIaNAqU0Vk-mr4WIlSAo4z5g

B3 Clutch:
http://drive.google.com/uc?export=view&id=1_sgRwAb4Pes7JxcnbCoMmrI3QYiKitwMAQ

K3 Clutch
http://drive.google.com/uc?export=view&id=1zPwc-aoQvUrWQmRSVvSryPAC4qCOg05n9g

K3 Clutch again cut close up of friction teeth. Notice the deformation:
http://drive.google.com/uc?export=view&id=1e7TT7ivTMvRTADUFRd-hr1AVUbbCYNyqhg

O-ring at K3 Clutch. This o-ring had broken down and there wasn't a lot left of it:
http://drive.google.com/uc?export=view&id=1H7vzLlRXXl4zlP7A01bMWqvecx-WGNPR2A

B2 Clutch:
http://drive.google.com/uc?export=view&id=1T2EhY7mF-dvLIQkjuTVrPzeJwfYqmHq13Q

B2 Clutch Again. Notice the deformation on the steels:
http://drive.google.com/uc?export=view&id=1zuvzA_4ShYli0H6sUq6uQWjh1UUG8aqlmQ

B2 Clutch Housing. Grooves/gouging present on the outer housing:
http://drive.google.com/uc?export=view&id=1uQKKDdDShVbgO__BUSmYzoeZkEMIO3ARWw

I'm concerned about the pitting at the bell housing at the oil pump. It looks like something must have gotten in the oil pump "chewed up."

I'm also concerned about all of the deformation on the surfaces that the clutches engage. How much is this is normal wear and what should be replaced?

__________________
George Carstens

Hi George,

Excellent documentation. If you have any other DIY tech articles that you've worked on or wrote; check out the link below. If we publish your article, we'll give you 10% off your next order.

Enthusiast Tech Article Submissions - Pelican Parts


-Dmitry

Well I was scratching my head on the bellhousing gouging and I think I realized what may have happened.

Another look at the oil pump picture and you might notice that there is no way for the oil pump to engage the torque converter. Both of the tabs are missing. I happened to find one of them though.

http://drive.google.com/uc?export=view&id=0B6yhLl0x55kdbXI1WEJEcHM1bkU

Seems like a failure that should have caused a lot more damage.

__________________
George Carstens

George,

Ohh you have a project on your hands....

I rebuild these, and many of your hard parts are just beat-up compared to a passenger car. The frictions look great. What kind of fluid where you running in it?

How come you did not up load the pictures on to the peach parts, so the pictures live forever as I have seen two great rebuild threads where people do these great DIY's but the pictures die-off five to ten years later because the pictures are externally hosted...

Anyways, what I would, so you are not buying a pile of hard parts. I would get a W220 from the self serve junk yard.

Row52 | Search Results

https://www.lkqpickyourpart.com/locations/


The bell housing is $500 or so dollars, but you do not have a picture of the whole inside of the bell housing as it might be identical to a M112/M113...You may just get a machine shop to one-thousandth or so. Pump gears are the same on all 722.6 and 722.9, but the steel portion of the pump mercedes updated to a roller bearing for some 722.9 and maybe some high-powered 722.6's too. I know Sunvalley transmission machines their own pockets for roller bearing on the steel pump portion, and the bell housing pump plate area... Now, you have seen this? Steel pump plate for this problem-look at half way down for the You-tube..

New revised 722.6 service manual - get it while can - Mercedes-Benz Forum

K2,B2&B3 I have only seen the aluminum like that. Again you may luck-out with a W220 S500. I would press-out the pinions to put new copper washers..

Output Shaft/Center Planet Pinion Washer - 78580C-W - Sonnax

B1 large cage is on S500/S600 transmissions, and they are never beat up, so can get one there with a large basket, and remember you have a bonded piston behind the basket that needs to be changed.

I want to say yours has the third generation sprag which is 0.92 in height, but measure what you have...

Make sure you replace this bearing, and the teflon seal, or you will kill your transmission...

Bearing & Seal Kit - 68410-02K - Sonnax

The bearing is SOB to remove without the proper extractor...

The steels are Identical on all these 722.6 and 722.9...

Make sure you are right at the minimum gap clearance on the frictions, so it will mean you will need to buy new spring clips...

Remember you will need new pump bushing and stator bushing too

Rear Pump Stator Bushing - 68915-01 - Sonnax

Pump Bushing - 68004-01 - Sonnax

if you can find someone to machine a larger pocket, I'd get a larger one..

Pump Bushing - 68004-02 - Sonnax

Ahhh Go with a CVC torque converter as it has the sonnax updates too..They are sold by Whatever it takes..

Torque Converters Distributors Page - Consolidated Vehicle Converters, Remanufacturing Torque Converters for Automatic Transmissions

Whatever it takes transmissions has a great exploded view diagram of the 722.6 on their site

https://www.wittrans.com/

Download the catalog to get the diagram

https://www.wittrans.com/catalog

All the best,

Martin

Double post

Martin

I'd have a close look at the damaged area as it might not extend into the pumping area.

There is a pump wear fix it plate but I haven't used one and am not sure if they need glued in or not. https://www.wittrans.com/parts.php?&type=722.6&group=HARDPARTS&notPictured=1&categoryNumber=2010&category=PUMP%20COMPONENTS

A78544E
Price: $30.07
Core Charge: $0.00
Available: 3
PUMP WEAR PLATE, 722.6/722.9

Also look here for info. http://www.atraonline.com/gears/2005/2005-09/2005-09_26.pdf
You will also need to get creative with your snap press by using various pieces of large dia exhaust pipe / bearing races. There is an L shaped snap ring that needs the spring compressed fully before it will come out.

Thanks for all of the information! I'm going to take some time and digest and get back with you guys.

I'd be more than happy to upload my pictures instead of linking them.

I don't know how many miles are on the clutches. The transmission was sold to me used with 180,000miles on it but I have a hard time believing that those clutches have that many miles on it. I think they may have been replaced at some point but that's hard for me to know for sure.

I use Titan Fuchs 4134 fluid.

__________________
George Carstens

If the trans was mostly highway miles, zero wear occurs on the clutches. And with adaptive electronic control, wear is minimized. This trans applies and releases clutches based on RPM feedback not a blind hydraulic valve body.

I rebuilt the trans in my 97 C280 at 161,000 miles due to a worn input shaft bushing. It wore just enough for the planetary to sing only after driving on a rough road ( this got things spinning off center ) The frictions looked as new, near as I could tell the trans was never rebuilt and filter was only a few years newer then the car. ( look at date codes on plastic parts )

A factory MB rebuild will have the part / serial number ground off the rectangular pad on the left side of the trans and a plate stuck on.

The frictions are beautiful. They never look that good consistently, so like 97SL320 said it was a highway van, but the transmission looks overheated from either heavy hauls, or long hill grades. The metal look black/burned, yet on a street car, or a AMG/600 car the friction faces are usually blue/black, and the half the frictions worn.

Now, you did not show us the frictions at the back of the transmission as they wear out fast on a passenger car. The B1 basket of frictions on a passenger car get very worn for lead-foot drivers, or anyone with a 600/AMG car. You can see that in the one of the YouTube....

The fluid that was used is great stuff...

Martin

All of the frictions look really good through-out the entire transmission. I haven't found a worn out one yet.

Explain the overheating comment. What do you see that causes you to believe that? In my short experience with this particular transmission, it has experienced long mountain climbs for sure driving in the pacific northwest. The fan weighs in at 9500lbs so this isn't a light duty transmission by any means.

__________________
George Carstens

yesterday,I was on a nag 1 trans site,,looking at high performance parts. One thing they said was prior to 1996 mercedes used double faced clutches in their trans.The only drawback was heat generated.i wondered why my sd trans at 368,000 miles shifts like new.Because its a diesel it does not see rpms high enough for heat.I wonder if these older clutches are used with a external trans cooler not heated by radiator,would they last longer.

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1999 w140, quit voting to old, and to old to fight, a god damned veteran

Here are some more pictures of both sides of the bell housing.

Attached Thumbnails

     

__________________
George Carstens

Most of the clutches are double sided in my 2006 sprinter transmission and the transmission cooler lines are tied into the radiator for pre-heating and cooling. I am adding an external cooler though due to the weight of my van.

I believe K1 may be the only clutch with single sided frictions.

__________________
George Carstens

In the name of searching for replacement internals, I am curious if transmissions out of Chrysler 300C, Dodge Magnums, or Grand Cherokees would have the internals I need. They are all supposed to have high torque capacity 722.6 transmissions. I know I wouldn't get the bellhousing or correct casing necessarily but perhaps the right internals. These cars are much easier to find at the junkyard than an S500.

__________________
George Carstens

Yes, you can go the dodge route, but(a big but.....) The height of your sprag will determine if you have third-genertation transmission, or the common 2nd generation types(+2000 cars). The third-generation will be super rare at the junk yard, and some mid to rear hard parts may be different from the 2nd generation....

Your bell housing looks like it is identical to M104, but I could be wrong if Identical to the M104? Then you need to find a 97-99 S320 to grab the bell housing, or call these guys to see if they can help you with some used hard parts:

LA Transparts

All the best,

Martin