Seth,

First, It is heat from the exposed four terminals in your pictures. The new conductor plate design has those covered up. Plus, everyone should be adding the plastic solenoid covers to the new conductor plate.

Second, timely fluid changes cool first before lubrication.

I would change the solenoid seals, clean or replace the regulation solenoid screen filters, and just like G-AMG wrote on one of his conductor DIY's. Change the regulation spring in the the valve body.

MArtin

 

Martin,

Thanks so much for your assessment it is most appreciated. I had suspected that the plastic casing of the Hall Effect Speed Sensor was "heat damaged" and was hoping I was not looking at a pending K2 Bearing Failure with associated Planetary Gear Catastrophe.

Fortunately the transmission is working fine both before as well as after my servicing. BTW your previously provided photos for the seal changes while performing my PLIL was "invaluable". I changed the pressure regulator spring in the valve body (my original did seem fine) since for a couple of bucks it was worth the piece of mind. I am glad I replaced the original conductor plate with the "updated" design.

Unfortunately my 722.605 did not have solenoid covers so I did not install them. I wish I knew! Oh well we keep getting smarter and learning from each other.

As you written in a previous post of yours:
"I failed english and math in high school, yet I went all the way to the top in math, and english...Paid the price, but knowledge is power..I read A lot on these cars. Went to junk yards and played doctor too, and I still do it...

Martin"


Thanks again,

Seth

 

Seth,

I need to be careful what I write ? :grin

You are welcome Seth. Everyone here is a winner who share their moments.

Conductor plate failure does not constitute K2 bearing failure, or a strain on the K2. Usually Conductor plate failures lead to limp mode, yet in your case your speed sensors were still working in this ruptured mode of the sensor.

Glad you are up and rolling, and did you reset the user Adaptation Values?

MArtin

 

Here's mine out of a ~135k mile S420 with complete failure from K2 bushing bearing, so I can vouch for the ATSG guide info. As K2 bushing bearing wears it allows misalignment of the input and output shafts, so the speed sensors end up getting rubbed by the windows. If your transmission has never been rebuilt with updated parts I'd seriously consider it. The pic is not a close up but you get the idea of what is going on.

 

I did reset my Adaption Values.

Could I expect any drivability "symptoms" PRIOR to the K2 bearing failure e.g. a whining or such or should simply I expect it will just go out on me with NO NOTICE or ability to get my parts and procedures in place to do the rebuild.

I hate the idea of tearing apart a "PERFECTLY" performing transmission for a rebuild 20K or 40 K miles before I need to.

Just curious if I would get a "heads up" or not.

Thanks,

Seth

 

Mine gave no warning. I even serviced mine and dropped the pan which showed nothing to worry about but I did not drop the valvebody and conductor plate.

If you end up with bearing rollers going through your planetaries, and you will know if it happens, drive in 4th and don't stop until you reach home. In 4th gear damage in minimised as all gears are locked 1:1. Other possibilities are slippage or wiped out speed sensors that will put you in limp mode.

If you want to preserve K2 bearing bushing as much as you can drive with the shifter in 4th and avoid time the transmission in N to minimise movement on the K2 bush surfaces.

Are they metal particles in the cracks on that speed sensor drum?

 

Hi Joe,


When you mention "avoid time with the transmission in N" does that also include P? (it's a locked N after all)

 

Seth,

Just like Joe said, no warning. I know someone who was told by transmission shop the fluid was okay, and few months later. The K2 went out... and destruction. If it happens on the highway, the car will stop.

MArtin

 

One last one Seth,

If for some reason you suspect the sound, put your fingers(spin the fan manually) between the fan and the fan shroud to find a collapsed motor mount(s).

Lastly, remove the serpenten belt, and start the car to make sure it is not the bearing to an accessory.

A pretty good mechanic I was working with had this whine noise, and thought it was the torque converter(it sounded like it was from there), and contemplating a rebuild since I told him why just change the torque converter? The belt cam off, it was the rear alternator bearing...

MArtin

 

Martin and Joe,

Thanks both you for your inputs it is most appreciated. Essentially I work to keep the car running "reliably" I realize that for our 17+ year old cars it is a challenge therefore my approach has been to perform preventative maintenance. Especially what we on the forum has considered “common problem part failures” e.g. the coolant Tee.

I realize this approach translates to changing out parts before they fail but that is the trade off for increased reliability. Although I don’t know if the fuel pump would have made the list or not based upon Martin’s recent break down. I suppose from your inputs, it is prudent to rebuild the transmission proactively. Therefore, I will do so prior to 200K (which is another 15K miles away).

Regards,

Seth

 

G-AMG took a similar approach as depicted with his recent failure of his CPS on one vehicle which stopped the car dead on the road and proceeded to change out the CPS on his other vehicle (proactively) to maintain the reliability. Interesting I believe the vehicle even had similar mileage to mine 180K miles

 

Seth,

I'm going to do a PM on a rare 2nd generation 722.6 on my 2002 E320 4matic wagon. It is rare because the rear bolts onto a transfer case, yet one would think it is the same as the ML transmissions, but my transfer case has gears, and the ML has a quad roller chain. It is rare because I have not found one of these cars at the junk yard, nor people parting one out.

I want to do a PM(rebuild soon) as the car has 180k it has been super reliable. It is a true " gas-up and go car" I just gas this car up, and do fluid changes. It has not needed anything, and I have put 80k miles in five years.

I have noticed these 722.6's of all generations that when K3 clutch (frictions) start wear out significantly. The rear pancake stack of clutch packs start to smash some hard parts at the rear, and ruin the slot where a sized retaining ring fits on the drum of the clutch pack. I just do not want to replace that part. The 2nd Gen 722.6 does not have a K2 bearing problem like the first generation, but I will change the K2 roller bearing.

I will do a full rebuild of replacing all the seals, frictions, front bonded piston, bushing bearings on the pump, and stator. A 722.6 one has to replace the torque converter as it contains frictions. Since it is a +2000 transmission, the are know for that bump in the 2 to 3 shift, so it will need a overlap kit to shift super smooth.

For you, A rebuild would be great, but what would be great is whoever does yours. I do not know if it is common practice to update the front and rear shafts with the new style of shafts which incorporate the K2 roller bearing. I think most shops just pop-out the old K2 bushing bearing with a new K2 bushing bearing, so their is not improvement in longevity as by going to K2 roller bearing the fluid changes are no longer a issue, or thoughts of failure.

Buying those two shafts from Mercedes will set you back $2000 for both shafts, so that is why I think most shops do not update the transmission. One would never know or feel the difference in the shifts. They do not have anything to do with the shafts. This is why I update these 722.6 V12 and V8's W140's with W220 transmissions.

Like I said before, I have never done a W140 722.6 I6 car. Not sure if it has four or three planetary gear shaft. If it has a four-planet, the donor transmission must come from W220 or W215. If it has a three planet gear shaft, A +2000 W210 or a +2000 W208 will work. This is the mystery with your car.

I hope it makes sense,

Martin

 

Martin,

I know my transmission is a 722.605. I know that the infamous K2 Bushing/Bearing because I checked with you several months ago.

I was planning on using Sun Valley Transmissions for the rebuild ($2K complete) since they gave me a good price and have an excellent reputation, the owner is Marc. I have been spoiled of late renting a lift so I could do the install I am just choosing not to.

I e-mailed Marc and asked him specifically:
1) "Based upon my photos is it possible that the casing of the Hall Effect Speed Sensor was cracked simply due to age/thermal cycling and is normal wear and tear?"
2) "Can you tell me if your rebuilt transmission for my vehicle 722.605 will be fitted with the “Updated K2 Bearing” which is more robust to replace the current sleeve bushing? "

Sun Valley Transmission Reply:
"Hi Seth

1) The cracked cover is normal for an old plate. The plastic degrades with age and cracks.

2) We always cut the shaft and install a roller bearing in it's place. The brass bushing was a big mistake.

Marc"

So it does appear I will be getting the upgrading K2 bearing with the rebuild. That does make me happy ;-)

Seth

 

Speed sensors on a W220 S500 722.633 with no physical damage or wear on K2 needle bearing. Mileage unknown:

 

Joe,

Revised conductor plate, but it is damaged as it has crack on the center.

Seth,

What SunValley is doing is milling the hole larger to accommodate a roller bearing. My understanding. The "Updated Mercedes" shafts from Mercedes are a bit larger in diameter, and one cannot just buy the one shaft with the updated K2 roller bearing. Both have to be replaced if the Mercedes shafts are bought from Mercedes, But again. Sunvalley is milling the pocket larger, and putting there own K2 roller bearing.

Martin

 

K2 Roller Bearing



Well as long as the rebuild will have the K2 Roller Bearing instead of the inadequate K2 Bushing/Bearing that should solve that weak link of this 722.6 transmission. I suppose Sun Valley Transmissions came up with a reasonable method to mill the hole larger to accommodate the roller bearing.

Thanks,

Seth

 

Yep, cracked, so they can just crack from age/use without the K2 problems having any effect.

 

Sun Valley Transmission out of Concord?
Watching this thread...

 

It is this sun valley..

Sun Valley Mercedes Transmissions

Right around where the 405, 5 & 14 freeways in Los Angeles Basin are at..

Martin

 

Good to know.
Any place a little more local to us?

 

Bumping this thread from a few months back. I just dropped the valve body out of my '97 S500 and it looks like one of the speed sensors is getting some abrasion from the drum. Trans (175K miles) was exhibiting shift flaring, usually on the 2-3 shift, would not ever go into limp mode. Inspection of the fluid and valve body showed a nice build up of sludge, brown fluid and some traces of copper. So does the evidence point to the early stages of bearing failure as I suspect?

I'm getting ahead of myself and have started looking for a rebuildable core, MAVAs comments in the earlier portions of this thread would lead me to believe I should go for a later 722.6 from a W220 (w/improved roller bearing shafts); I got a lead on a trans from an '02 S430, would this work? Are the bell housing patterns between the M119 and M113 engines the same?

 

Dan,

Here is what you need, but look at post 12

http://www.benzworld.org/forums/w140-s-class/2212618-722-6-slip-shudder-d-r.html

The bell housings ARE NOT the same..

the 2-3 bump is the shift valve with too much leakage...A sonnax kit will solve that problem..See post 4

http://www.benzworld.org/forums/w210-e-class/2397801-paging-mava-722-6-valve-body.html

Martin

 

Thanks for the links Martin, I had made a call to Sun Valley Transmission earlier and they basically told me the same thing: the only thing the W220 trans would get me is updated innards I'd have to swap into my W140 case.

I have heard of the Sonnax kit and I suppose the cost and work involved won't kill me if I'm ready to spring for a rebuild. Two concerns though: I have yet to read about a beginning to end Sonnax kit success story, I'd feel better about trying it if at least two people could report first hand experience of it fixing a problem like mine.

Second, the fluid and sludge may not have been so terrible but my main concern was the scuffed speed sensor, is that not clear evidence that excessive bearing clearance is causing the sensor to take a beating? While the valve body was off I did reach through the sensor hole to see how loose the drum was, it did move up and down quite a bit but I don't have a point of comparison. I regret not trying to spin it in both directions, as I understand it should only rotate in one direction, right?

 

Dan,

You are welcome Sir!

If you pulled the conductor plate/valve body, basically most of your battle is done. To unscrew a few plates on the valve body is peanuts to swap out those shift valves out.. Here is a thread ..

722.6 Transmission Refresh. DIY and questions. - PeachParts Mercedes ShopForum

I did mine a few weeks ago..

These transmissions(722.6) are very sludgy compared to the older generation as some major internal parts are made from aluminum instead of steel...

All the best,

Martin

 

Dan O, pics of the scuffing might help a free remote diagnostics.

 

Yeah, pics would've been great but unfortunately, grabbing my cell phone with atf everywhere never entered my mind. I'm sure I'll end up trying the Sonnax kit and then I'll get a second opportunity to take pics and check rotation of the internals.

On the other hand, I'm not looking forward to the whole drain, drop and refill routine again only to find that the Sonnax kit did nothing. Forgive me for being doubtful but past experience has taught me that if a problem has two potential causes (one easy fix and the other not so easy) then nine out of ten times it will be the latter. With that, would there be any amount of sensor scuffing that could be considered acceptable? I'm thinking in a healthy transmission the sensor and drum will never make contact with one another.

I'm willing to try the Sonnax kit simply to see if anything changes; if it fixes my problem then super, if not then there will be a documented case of the kind of situation it can't correct.