Advice/best guess for 722.9 transmission code p0894
#1
Advice/best guess for 722.9 transmission code p0894
Hi,
im new to this forum so apologies if I知 posting in the wrong section. I recently was given a 2006 W211 e350 140,000 miles with 722.9 transmission currently in limp mode. I had MB replace the SBC and they suggested I service the transmission and quoted me $$$ to basically change the fluid and replace the filter.
I did did it myself and even inspected the solenoids in the valve body for debris. The fluid in the transmission was very old and smelled burnt but not scorched. The oil lacked viscosity but contained little debris and no obvious signs of clutch material. I inspected the outside of the filter but now wish i had cut opened the filter and looked inside for debris.
I put everything back together with new fluid and the car still will not shift past 2nd. Reverse is good and between 1st and 2nd is very smooth. I知 hoping to get some feedback on what the problem might me because I致e heard 2-3 different causes each that require a substantial investment of money and time. The worst being changing the torque converter and transmission. The other 2 are there is a burnt clutch pack and the debris is on the inside of the filter or the valve body is bad.
Any help or suggestions is greatly appreciated. I don稚 mind putting in the work myself and fairly competent with cars and have access to a lift, I知 just not interested in sinking a bunch of money into an old lady car. Not that my wishes have any impact on what repair is needed, I知 just throwing it out there for mercy from the Mercedes Gods for an easy fix.
im new to this forum so apologies if I知 posting in the wrong section. I recently was given a 2006 W211 e350 140,000 miles with 722.9 transmission currently in limp mode. I had MB replace the SBC and they suggested I service the transmission and quoted me $$$ to basically change the fluid and replace the filter.
I did did it myself and even inspected the solenoids in the valve body for debris. The fluid in the transmission was very old and smelled burnt but not scorched. The oil lacked viscosity but contained little debris and no obvious signs of clutch material. I inspected the outside of the filter but now wish i had cut opened the filter and looked inside for debris.
I put everything back together with new fluid and the car still will not shift past 2nd. Reverse is good and between 1st and 2nd is very smooth. I知 hoping to get some feedback on what the problem might me because I致e heard 2-3 different causes each that require a substantial investment of money and time. The worst being changing the torque converter and transmission. The other 2 are there is a burnt clutch pack and the debris is on the inside of the filter or the valve body is bad.
Any help or suggestions is greatly appreciated. I don稚 mind putting in the work myself and fairly competent with cars and have access to a lift, I知 just not interested in sinking a bunch of money into an old lady car. Not that my wishes have any impact on what repair is needed, I知 just throwing it out there for mercy from the Mercedes Gods for an easy fix.
Last edited by Mrg415; 03-13-2019 at 03:04 AM. Reason: Spelling
#2
Junior Member
Due to a diagram I found, in 1st gear B2, B3 brakes and K3 clutch are applied, in 2nd B1, B2 brakes and K3 clutch.
3rd gear would require B2 brake, K1 and K3 clutches applied, so maybe K1 clutch (only needed for 3rd, 4th and 5th gear) canエt be actuated.
There may be a problem with the Y3/8Y2 solenoid (the one closest to the plug) that controls K1 - changing this out is worth a try.
Btw: Iエm lawyer by profession, so donエt take my thoughts too serious
3rd gear would require B2 brake, K1 and K3 clutches applied, so maybe K1 clutch (only needed for 3rd, 4th and 5th gear) canエt be actuated.
There may be a problem with the Y3/8Y2 solenoid (the one closest to the plug) that controls K1 - changing this out is worth a try.
Btw: Iエm lawyer by profession, so donエt take my thoughts too serious
Last edited by AUTOdidact; 03-13-2019 at 11:51 AM.
#3
Hi,
thanks for the reply. I had the same thought and that’s why I checked and cleaned the solenoids. Maybe should have replaced that one. The lack of clutch material is what makes me think it’s not something internal but that doesn’t mean that one or the clutch packs isn’t smoked. Btw I’m a lawyer as well so I’m sure there’s some joke to be made. “Two lawyers are working on a car...”
thanks for the reply. I had the same thought and that’s why I checked and cleaned the solenoids. Maybe should have replaced that one. The lack of clutch material is what makes me think it’s not something internal but that doesn’t mean that one or the clutch packs isn’t smoked. Btw I’m a lawyer as well so I’m sure there’s some joke to be made. “Two lawyers are working on a car...”
#4
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2008 E350 4Matic, 2011 E350 4matic
No real advice, but maybe get a code scanner like the Autel Diaglink that can scan MB specific codes and maybe you'll get some transmission specific codes that will help you better troubleshoot. About $95 on Amazon.
#5
Junior Member
Of course the sensors may not be able to distinguish between slippage due to worn clutch material and the clutch turning freely because it isn't applied...
Last edited by AUTOdidact; 03-14-2019 at 01:50 AM.
#6
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#7
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If you still have old ATF have it analyzed: https://www.blackstone-labs.com/?ses...tgvjm%29%29%2F this will confirm if one or more internal components might be failing.
#9
Thanks, that’s is a really good idea. I didn’t save a sample of the old fluid but is it reasonable to believe that the new fluid mixed with the fluid in the torque converter would be sufficient to test for contaminants? I have a Nag2 or I assume I do because that’s written on the conductor plate assuming it’s the original.
#10
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#11
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2016 E350 4Matic; 2018 GLC300 4Matic; 2005 C55; 2003 360 Modena
The attached is from an MB document that I was only able to crop this piece from. I have other information if you let me know your email.
#12
I got an AMG tech with his $22,000 Mercedes scan tool who is going to inspect it for me. He thinks the fluid is still dirty and the level is not set right. He ran it over with MB engineers and they all say it痴 the fluid. But none of them have seen the car but they are confident. I brought up the possible solenoid issue and they say it won稚 be that but I知 going to try it since I知 going to have the pan off.
#13
Junior Member
I got an AMG tech with his $22,000 Mercedes scan tool who is going to inspect it for me. He thinks the fluid is still dirty and the level is not set right. He ran it over with MB engineers and they all say it痴 the fluid. But none of them have seen the car but they are confident. I brought up the possible solenoid issue and they say it won稚 be that but I知 going to try it since I知 going to have the pan off.
To my experience a fluid change may improve shift quality but never fixes a "real" issue. You should in any case also change the above mentioned shift solenoid, they are quite cheap.
Last edited by AUTOdidact; 03-17-2019 at 07:28 PM.
#14
For MB workshops it's always the fluid because they can't / are not allowed to do anything else on the transmission
To my experience a fluid change may improve shift quality but never fixes a "real" issue. You should in any case also change the above mentioned shift solenoid, they are quite cheap.
To my experience a fluid change may improve shift quality but never fixes a "real" issue. You should in any case also change the above mentioned shift solenoid, they are quite cheap.
Its odd because the tech told me they use aftermarket oil filters when you pay them for their expensive oil change. Anyway, I ordered a new solenoid just in case it痴 bad, might just put it in anyway as a physical malfunction would not show when I check the resistance. Is there a safe voltage I can apply to hear or see it open/close?
Any tips on checking/cleaning the valves without opening the valve body up? The oil was in really bad shape, any chance the valves are just dirty? 150,000 so there is still metal debris and maybe it plugged up the solenoid and/or valves?
Thanks for all the suggestions, I appreciate them.
#15
Super Member
Just curious if the drain and refill also included the fluid in the torque converter. The reason I ask is because these transmissions hold a good amount of fluid and it doesn't drain out very easily. Some manufacturers recommend doing 3 drain and refills to get enough fresh fluid in and the old fluid out.
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I got an AMG tech with his $22,000 Mercedes scan tool who is going to inspect it for me. He thinks the fluid is still dirty and the level is not set right. He ran it over with MB engineers and they all say it’s the fluid. But none of them have seen the car but they are confident. I brought up the possible solenoid issue and they say it won’t be that but I’m going to try it since I’m going to have the pan off.
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Just curious if the drain and refill also included the fluid in the torque converter. The reason I ask is because these transmissions hold a good amount of fluid and it doesn't drain out very easily. Some manufacturers recommend doing 3 drain and refills to get enough fresh fluid in and the old fluid out.
#19
Hi,
im new to this forum so apologies if I知 posting in the wrong section. I recently was given a 2006 W211 e350 140,000 miles with 722.9 transmission currently in limp mode. I had MB replace the SBC and they suggested I service the transmission and quoted me $$$ to basically change the fluid and replace the filter.
I did did it myself and even inspected the solenoids in the valve body for debris. The fluid in the transmission was very old and smelled burnt but not scorched. The oil lacked viscosity but contained little debris and no obvious signs of clutch material. I inspected the outside of the filter but now wish i had cut opened the filter and looked inside for debris.
I put everything back together with new fluid and the car still will not shift past 2nd. Reverse is good and between 1st and 2nd is very smooth. I知 hoping to get some feedback on what the problem might me because I致e heard 2-3 different causes each that require a substantial investment of money and time. The worst being changing the torque converter and transmission. The other 2 are there is a burnt clutch pack and the debris is on the inside of the filter or the valve body is bad.
Any help or suggestions is greatly appreciated. I don稚 mind putting in the work myself and fairly competent with cars and have access to a lift, I知 just not interested in sinking a bunch of money into an old lady car. Not that my wishes have any impact on what repair is needed, I知 just throwing it out there for mercy from the Mercedes Gods for an easy fix.
im new to this forum so apologies if I知 posting in the wrong section. I recently was given a 2006 W211 e350 140,000 miles with 722.9 transmission currently in limp mode. I had MB replace the SBC and they suggested I service the transmission and quoted me $$$ to basically change the fluid and replace the filter.
I did did it myself and even inspected the solenoids in the valve body for debris. The fluid in the transmission was very old and smelled burnt but not scorched. The oil lacked viscosity but contained little debris and no obvious signs of clutch material. I inspected the outside of the filter but now wish i had cut opened the filter and looked inside for debris.
I put everything back together with new fluid and the car still will not shift past 2nd. Reverse is good and between 1st and 2nd is very smooth. I知 hoping to get some feedback on what the problem might me because I致e heard 2-3 different causes each that require a substantial investment of money and time. The worst being changing the torque converter and transmission. The other 2 are there is a burnt clutch pack and the debris is on the inside of the filter or the valve body is bad.
Any help or suggestions is greatly appreciated. I don稚 mind putting in the work myself and fairly competent with cars and have access to a lift, I知 just not interested in sinking a bunch of money into an old lady car. Not that my wishes have any impact on what repair is needed, I知 just throwing it out there for mercy from the Mercedes Gods for an easy fix.