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Discussion Starter #41
A. I do have a dipstick for the project :)

B. Why should I change the spring since it's not broken at least that's what I assume? I didn't remove all the valves/springs from the body for the cleaning I will check on the spring to confirm?

C. I didn't see the mesh filter for the pressure solenoids when I remove them on this valve body for the area you are talking about the car was made in 11/1996.

D. I don't think shifter bushing is the problem, was able to move in gears after the car was sitting for several days before I started the work, the fluid containment is the main problem I want to solve and to get as much of the containment out as possible before a flush.

From repairing many 722.6 trannies here is the skinny:

a) your dipstick is everywhere on fleabay for under 10 bucks

https://www.ebay.com/sch/i.html?_from=R40&_trksid=p2334524.m570.l1311.R1.TR1.TRC0.A0.H0.X722.6+dip.TRS0&_nkw=722.6+dipstick&_sacat=0&LH_TitleDesc=0&_osacat=0&_odkw=722.6

B) do not forget to change this spring:

https://www.sonnax.com/parts/2313-regulating-pressure-control-valve-spring

It can cause this too:

https://www.benzworld.org/forums/r129-sl-class/2966474-transmission-problems.html

C) I would not separate the valve body apart as you can really open Pandora's box. Yes it is grimy, but just clean the gunk with swabs and paper towels. 99% the problem is not there, yet do add the mesh filters filters the early 90's 722.6 did not have under the two black regulation solenoids...

D) check your shifter bushings as no movement can be that like this guy who was going to get hosed at the dealer:

https://www.benzworld.org/forums/r230-sl-class/2994757-transmission-issue.html

E) No movement is something internal in the drive train, but it can be the two black solenoids and they fail mechanically more than electrically. It is not the conductor plate as you could have it disconnected the car will still move with second and reverse(clunky but it will move). Broken spring on the overlap shift valve could do it too, but you tried driving in winter and summer modes(W n S) where summer is 1st gear shifts and winter is 2nd gear shifts..

Make sure you have fresh oil and a filter.

All the best,

Martin
 

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Discussion Starter #42
Update

So wanted to provide an update was able to wrap up the valve body and reinstall it.

Drained the engine block and remove the old radiator (it was a pain) pics 6 and 7. Ran some new coolant from the thermostat opening to drain out the water that I used to flush it.

Tested the solenoids before install they passed the residence and connector test with 12V riding mower battery.

Checked the valve spring looks good with the length spec.

Different sources are telling me different spec. for torque on the drain pan and plug (117 and 122 in/lbs) so used best judgement.

Any suggestion on what to do with bracket that is hard and in the way when installing the new the new radiator I don't want to move the evaporator too much. I think the car was involved in a front end collision and the bracket was not installed correctly this is from the welding that I observed on the frame.

Hope to wrap this up tomorrow.:grin
 

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If that's the lower radiator support bracket, it is not screwed in. It's welded in, and replacement requires it to be welded just like the original one.

Try to fit it anyway, if you can't, then maybe bend it out of the way just enough.
 

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Discussion Starter #44
Finally finished and first try.

Hello,

I finally got everything put back together the new radiator is working great the flush and new coolant refill is great. However, I am confused on the ATF flush process or if I am doing something wrong. I filled the transmission up with about 7.5L of Shell 134 and tried the flush out of the return line on top of the radiator. When I turned the car on and left it in park it started to come out into the bucket, but was looking like it had too much air pockets (1st video) also it was slow flowing, I've seen others do it and it was a quick flow to fill the bucket, am I doing this correctly? Whatever drained out I refilled also.

The other thing is the dipstick was measuring as if nothing was showing up between the cold/hot marks, I can confirm that there is no leaking anywhere so what is happening to the fluid. BTW, the dip stick does not go in all the way about 10" is still out I wonder if this is by design?

I didn't take the car out on the road yet since I didn't want to get stuck but, was able to move through all the gears on the gear shifter N>D was hard at first, I am able to move the car so the transmission is engaging but sounds bad from Reverse to Drive and vice versa almost like rusty hinges on a door (2nd video) the car was warmed up for almost 15 minutes at the time of the video.

My plan for now is to leave the car overnight and measure again in the AM and actually try the flush again from the cooler line and see if it improves, and then drain the torque converter and pan again and refill with Fuchs ATF.

The good part is that the spinning noise at startup probably from the torque converter, the jumpy RPM reading, and hard thump noise getting into gear issues are gone.

BTW, what is the actual capacity for ATF on this transmission, I am seeing between 7.5 - 9 liters in my research what is the correct amount?


 

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Did you drain the pan or also the torque converter? If you drained the torque converter, as I understand, you shouldn’t pour everything in as an initial fill. Pour in as much as drained from the pan and a quart more. Start the engine and run through the gears to let the torque converter fill. If it doesn’t engage, pour in half a quart. Run through the gears again. Repeat until the transmission engages or you pour in as much as you drained in total. For me it always engages before I pour in as much as was drained. The engine is running the whole time.

If you didn’t drain the torque converter, 7.5 quarts is way overfilled.

The dipstick is a factory tool. It only goes in so far. 10” extra is probably right.

You only need to see the tip wet since the transmission is cold. You should be able to drive the car normally with that much cold fluid. Get it to operating temperature (too hot to touch) then adjust to the right level.

If you drained the torque converter, I don’t understand the flush. Even with coolant contamination, you could have flushed the coolant lines separately.

Sixto
98 E320s sedan and wagon
02 C320 wagon
 

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Discussion Starter #46
Tabijan -

I did drain the torque converter and since this was my first time I didn’t measure accurately what came out. I wanted to flush because I wanted to make sure the dirty fluid from the gears and mechanical parts get cleaned out since I can’t take all those parts out to clean also wanted to flush to get the ATF coolant return lines cleaned since I didn’t open then except to reconnect the new radiator.

Right now the transmission is engaging so the problem that I started with is looking like it’s fixed. I just wanted to make sure the second drain I do I will add the amount that you mentioned to prime the torque converter before filling it completely
I hope this helps clear up .

Pintu
 

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If you have 7.5 fresh quarts in there, you’re close to done. Get it to the right level, drive a few hundred miles then drain only the pan a couple more times and call it good.

Sixto
98 E320s sedan and wagon
02 C320 wagon
 

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ATF isn’t going to get to 80*C idling. You need a solid 20 mile drive, not stop and go, to get there.

That’s what frustrates me about checking ATF level - my commute is 13 miles each way. I have to go out of my way to get ATF hot enough to take an accurate reading.

Sixto
98 E320s sedan and wagon
02 C320 wagon
 

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Didn't you just buy an Foxwell scanner ? You should be able to read the ATF temp from the scanner when the transmission is in gear. You should aim for a minimum of 60 degrees C when doing the level check.
 

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Discussion Starter #50
Didn't you just buy an Foxwell scanner ? You should be able to read the ATF temp from the scanner when the transmission is in gear. You should aim for a minimum of 60 degrees C when doing the level check.
Yes, I did get the Foxwell NT510 and looked for the transmission temperature both at 38pin and DLC connection and I can't find it under live data, I did fine ECT temperature. I will try again when I get home tonight.

Pin2
 

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First, Golden rule never flush/fluid exchange a 90's 722.6

Second, the fluid will get hot idling, but just add fluid to the cold mark and let it idle more time..

If you want to drain your radiator, drain it to clean pail, so you can re use it. Now, if you got the dark Mercedes then it may be hard to visually see if you Zerex G05 Pee-color coolant. You can spot oil cooler failure...

Low on fluid causes all kinds of jerky, or uncontrolled symptoms on these trannies. It is better to be high than low. I've done a quart too much and no big deal, but a quart to low varies on how old the tranny is as it very loose it is with large gaps on the clutch packs, so that takes time to pressurize, or not pressurize at all..

The fluid is the "blood" to make this thing work.. It does not matter if you have Fuch's, Shell, Mercedes, or Valvoline Max-life, but not enough is not enough... Contaminated with coolant is total no-go-condition..

Martin
 

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Ahh.. No need to get scientific with it-"we are not building satellites here" with a temperature meter . The hot and cold marks are just fine.. If you really want to get scientific, measure the thermister on the conductor plate with the engine off. The resistance is dead-on on a Mercedes Brand conductor plate. See the link below, and look at the attachment...

Now what I would measure is the thermister on the conductor plate as it is responsible to longer to shorter shift delays based on temperature, yet I have never contested on what these trannies(722.6) do if the thermister is open, or at the wrong resistance (by a lot) based on the temperature. You can measure it at the TCM

https://www.benzworld.org/forums/w140-s-class/1839898-722-6-cold-weather-pls-help.html#post7039434

Martin
 

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First, Golden rule never flush/fluid exchange a 90's 722.6

Second, the fluid will get hot idling, but just add fluid to the cold mark and let it idle more time..

If you want to drain your radiator, drain it to clean pail, so you can re use it. Now, if you got the dark Mercedes then it may be hard to visually see if you Zerex G05 Pee-color coolant. You can spot oil cooler failure...

Low on fluid causes all kinds of jerky, or uncontrolled symptoms on these trannies. It is better to be high than low. I've done a quart too much and no big deal, but a quart to low varies on how old the tranny is as it very loose it is with large gaps on the clutch packs, so that takes time to pressurize, or not pressurize at all..

The fluid is the "blood" to make this thing work.. It does not matter if you have Fuch's, Shell, Mercedes, or Valvoline Max-life, but not enough is not enough... Contaminated with coolant is total no-go-condition..

Martin
I agree. People seem to be exaggerating the overfill above the hot mark. I also heard that a quart overfill will not really cause much of a problem (not that you should intentionally overfill), as the excess will p*ss out from the vent holes when the ATF gets hot. The overfill will not cause foaming, if the float that separates the sump from the gearset chamber does its job properly and isolates the chamber from the sump, when pressed up by the ATF.

It is the low ATF condition that causes foaming and drop in pressure as the pump will suck in air as well as the ATF. Then you will have slippages and all sorts of strange shifting conditions.

The ATF temp sensor faults will be flagged a 115 and 116 at the TCM reading.

If one of these occur, the TCM will default to a value which may affect shifting, but will not cause a limp mode or slipping.
 

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Discussion Starter #54 (Edited)
Marvin and Mrboca

So what I am understanding is that "adding" more fluid is best option to get the tranny to work normally. I did have it open for almost 2 weeks with the pan and valve body out and did a complete drain not literally) but you get my point.

Marvin - I changed the radiator because the old Valeo one was 22.5 years old based on the date code on it, I went with the Nissins one that everyone recommends. This was to solve any future problem with heating and further coolant /fluid issue.

How can I be sure if the pressure solenoids are working, like I said earlier and in the videos R, D,4-3-2-1 has slight vibration and when pressing accelerator RPM goes up and speed goes up but no more than 10-20MPH and sudden drop.

I am testing this while the front end is on ramps and back is off the ground. I would love to do this on the road but concerned I will get stuck which is not a problem but, my driveway into the garage has 15-20 degree incline this worries me.

Also, I torqued the solenoids to 70in/lbs and the bracket looked little bent down holding the conductor plate is this normal now I am thinking that I might have overtightened them?

ALso getting the adapter plug back into the connector was a struggle just like pulling it out was. I use a rubber mallet to slowing tapping it in, with all the pins aligned. The plug didn't want to go in easily to I also tapped it and went it with the white cap turning with it. Could hitting this with the mallet damage it.
 

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Discussion Starter #55
Ahh.. No need to get scientific with it-"we are not building satellites here" with a temperature meter . The hot and cold marks are just fine.. If you really want to get scientific, measure the thermister on the conductor plate with the engine off. The resistance is dead-on on a Mercedes Brand conductor plate. See the link below, and look at the attachment...

Now what I would measure is the thermister on the conductor plate as it is responsible to longer to shorter shift delays based on temperature, yet I have never contested on what these trannies(722.6) do if the thermister is open, or at the wrong resistance (by a lot) based on the temperature. You can measure it at the TCM

https://www.benzworld.org/forums/w140-s-class/1839898-722-6-cold-weather-pls-help.html#post7039434

Martin
How can I measure this at the TCM?
 

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The won't go more than 10 or 20 because the front wheels are not moving. ASR is kicking in and preventing wheel spin. Even with ASR off it does not turn off 100 percent.
 

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You will not get a good test with the wheels up in the air. You will get traction errors as shown in the video. The wheel sensor information is broadcast over the CAN bus, and monitored by the TCM and the ECU. The TCM will compare it with the rpm sensors data and you probably get fault codes as you run the car like this. The ECU will also be affected to reduce the engine power when the "skid" is detected. These tests are done with the brake and engine regulation functions disabled.

Did you cover the o rings with ATF prior to inserting the plug adapter ?
 

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You could unplug the abs and asr module and then do the same test with wheel in the air.... But then would need a scanner to reset the codes.
 

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You could unplug the abs and asr module and then do the same test with wheel in the air.... But then would need a scanner to reset the codes.
This is from Startek for M104 :

Notes regarding performance/speedometer test:
Disconnecting the ESP/ASR/ETS/ABS control modules is not allowed. The engine control module and transmission control module rely on these modules to supply the VSS data via the CAN bus.

To disable the brake and engine regulation function of the ESP/ASR/ETS/ABS control modules:

A. Working without HHT
Ignition: OFF .
Connect HHT adapter to data link connector (X11/4).
Bridge sockets 1 and 6.
Engine: Start (ESP/ASR/ETS/ABS MIL must illuminate!).

B. Working with HHT
Ignition: OFF .
Disconnect front axle VSS sensor connector (ESP/ASR/ETS/ABS MIL must illuminate!).

When work is completed, reconnect VSS sensor connector and erase DTC's with HHT!
 

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How can I measure this at the TCM?
I wrote it on the thread of the link, but here it goes again!

It will be on the small connector-the one with the CAN bus twisted wires. It will wires 33 and 34, and the shifter must be out of park. See the attachment.. :nerd

Page 102 has the procedure too. I just given you what that resistance means. Use the temperature read from the cluster to get an idea from a cold car resistance should be. Hot car will be totally different.

Page 104 has the pin-out of the connector on the transmission wire harness at the TCM... The connector has these cable-ties at the top, and on has to pry the connector cover to get access to the top of the connector, or just unplug it and shove a narrow spade connector as normal test meter leads do not fit in the holes to get a measurement.

Now my next easy to do test that can give you these problems is the shifter cannot be indexing properly on the transmission, so you are "in between" shift points(similar to bad shift bushing). Block the front of the rear tires and rear of the tires as this is dangerous to do out of park. I would disconnect the shift linkage at the transmission arm while in drive to verify the rod is not forcing the arm front or back. This no-drive is caused a only a few things, and it is not the conductor plate. Like I said before even with the plug disconnected at the conductor plate you would get a very clunky 2nd gear and reverse with NO slippage.

I do assume your TCM is clean too, and the fuse is not blown too.. How I clean it:

https://www.benzworld.org/forums/w210-e-class/2036305-high-mileage-questions-testimony-please.html#post9039089

Sadly these transmissions do not have pressure taps like the old trannies(722.3-722.5). Now for some reason lately there has been a rash of oil pump failures, yet maybe these trannies are just exploding due to age. I assume because you made the "Flush" there was ATF fluid flow of the cooler exit line? is this correct?

Marvin and Mrboca

So what I am understanding is that "adding" more fluid is best option to get the tranny to work normally. I did have it open for almost 2 weeks with the pan and valve body out and did a complete drain not literally) but you get my point.

Marvin - I changed the radiator because the old Valeo one was 22.5 years old based on the date code on it, I went with the Nissins one that everyone recommends. This was to solve any future problem with heating and further coolant /fluid issue.

How can I be sure if the pressure solenoids are working, like I said earlier and in the videos R, D,4-3-2-1 has slight vibration and when pressing accelerator RPM goes up and speed goes up but no more than 10-20MPH and sudden drop.

I am testing this while the front end is on ramps and back is off the ground. I would love to do this on the road but concerned I will get stuck which is not a problem but, my driveway into the garage has 15-20 degree incline this worries me.

Also, I torqued the solenoids to 70in/lbs and the bracket looked little bent down holding the conductor plate is this normal now I am thinking that I might have overtightened them?

ALso getting the adapter plug back into the connector was a struggle just like pulling it out was. I use a rubber mallet to slowing tapping it in, with all the pins aligned. The plug didn't want to go in easily to I also tapped it and went it with the white cap turning with it. Could hitting this with the mallet damage it.
You are right on with the torque. Those clamps are sprung downward

Ahh the solenoids are tricky as most fail mechanically, and not electrically... The 1-2 shift is the same solenoid for 4-5, but these cars have "W and S" S= Start in first gear W=Start in 2nd gear... Have you tried the W and S switch if it does anything for you? I do assume the codes have been cleared? The 90's cars have a binary out to the shifter.

All I can say for this 10-20mph and then drop is

A) A solenoid gets hot and drops out
B) A seal in the transmission is just worn and cannot hold the pressure
C) A friction pack has too much of a gap from being worn out, and cannot sustain the squeeze-pressure to hold the gear.

At this 10-20mph drop-out, does it happen at all gears. Try it manual by holding each gear

The Connector, I've had to do that a few times on clients cars, but are you missing the little heat metal shield that protects the connector from getting twisted from the exhaust pipe heat.

Ohhh your garage sounds like mine what I had. I had similar problem with my beater S500 which mine I would get about 45 seconds of drive time, but enough to go up the drive way, and that was the last of that problem as I drove it for the last time in the broken state until I pulled the tranny and rebuilt it there in the garage.. You too can do that as i guided a few on doing a rebuild, but before that I would swap the black solenoids from 2004/2005 ML/C/E/S. Now in my neck of the woods i can get a whole valve body with solenoids(and conductor plate) for under $100, but your car being a 97 may have issues with a revised valve body as the late 97 will tolerate +2000 valve body, yet the symptoms are delayed engagement at every stop for about 10-15 seconds. I do not know if a 98 TCM would solve this as I know this +2000 valve body works fine on a 98. At the minimum I would try the black solenoid replacement with some junk ones, and you could swap your shift solenoids too.. Make sure you have insertion resistance of the shift solenoids as they can cause that. The two o-rings on each shift solenoid must be malleable, and not hard. Sadly Mercedes DOES NOT sell those o-rings, but one has to buy the entire solenoid, yet those o-rings are included in nearly all 722.6 aftermarket rebuild kits

I agree. People seem to be exaggerating the overfill above the hot mark. I also heard that a quart overfill will not really cause much of a problem (not that you should intentionally overfill), as the excess will p*ss out from the vent holes when the ATF gets hot. The overfill will not cause foaming, if the float that separates the sump from the gearset chamber does its job properly and isolates the chamber from the sump, when pressed up by the ATF.

It is the low ATF condition that causes foaming and drop in pressure as the pump will suck in air as well as the ATF. Then you will have slippages and all sorts of strange shifting conditions.

The ATF temp sensor faults will be flagged a 115 and 116 at the TCM reading.

If one of these occur, the TCM will default to a value which may affect shifting, but will not cause a limp mode or slipping.
You are right, it will exit from the top vent half-way down the transmission, or come out right behind the torque converter.

Yes on the error code if it opens up, but not sure if the sensor is way off it's resistance point.. I do not know on the limp or slippage

Martin
 
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