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E320 1997 with Transmission issues

15K views 22 replies 9 participants last post by  Check Codes 
#1 ·
Hi there!

I´m new in this forum and would highly appreciate your help.

I´ve owned my 1997 E320 for the last 5 years and have never experienced any serious problem until now. During the past two weeks I have been experiencing some kind of "jerking" or hard shifting every time the transmission upshifts or downshifts:(. This is done 80% of the time (sometime it shifts OK without any jerking or impact feeling in the transmission). The mechanic that I user (Mercedes Benz dedicated shop) change transmission and differential fluids about 6 months ago and he already checked the fluid level and is clean and with correct level (no leaks at all). He also checked for any transmission error codes but he did not find anything and according to his computer,the transmission solenoids are operating OK.
The car performs perfectly during regular driving without any gear shifting but any time it upshifts or downshifts you can feel a small to moderate "jerk".
Could anyone let me know any ideas of what could the problem be?

I´d appreciate your ideas.

Thank you very much in advance!
 
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#2 ·
Sounds like you have done your best. The difficulty is that your description and what you feel while the car is shifting is very subjective and extremely difficult to start a diagnostic path.

If presented with this situation, I would have loads of questions and would test drive the vehicle to help me narrow down a suspect. That is just not possible.

In any event and with the absence of all that, All I have to offer is to lengthen the shift pattern. How do we do that? We do that by driving and then depressing the kickdown switch which is located in the foot well behind the accelerator. This action will send a message to the transmission control module that will make upshifts and downshifts take place at higher engine speeds------ie, lengthen the shift pattern. Ding How!!
a message to the
 
#3 ·
Dear Plutoe:

A few hours ago I performed a procedure to reset the "Transmission behavior" that I found in this forum. This consist in depressing the accelerator pedal while having the ignition switch in the on position (engine off). This seems to have reset the Transmission and ease the problem but it still persist when shifting from 2nd to 3rd gear.

I´ll try the procedure you mention, but could you clarify if by depressing the switch you mean accelerating the car until it shifts downward to the next lower gear?
Would appreciate more details about this procedure.

Thank you very much for your input.
 
#5 ·
Dear Atmsmshr:

I already performed this procedure and the car improved the shifting between 1st and 2nd gear but the rest of the gears still feel a moderate jerk different than before but the issue still remain.
Thanks for the link.:thumbsup:


Klrgator
 
#6 ·
What about any springs in the tranny? That is one more thing to consider.. My W210 has a case of the jerks also - checked the valve body and the spring is fine (dang) - so will drive it for now, planning on a rebuild one day..
 
#7 ·
Greggster:

Thanks for the advice. How do you check the springs in the tranny? I assume you may need to open it. Where are these located?

As I mentioned before, the jerking occurs when upshifting or downshifting. This is the same feeling you have in a manual transmission when you release the clutch to fast.
 
#8 ·
Always start with the easy checks (like adaptive reset) and work your way up the chain of harder and more expensive. Well, this one leaps up the chain pretty quickly.

To check the springs means you have to drop the tranny pan, and lower the valve body. The springs are on the side of the valve body. When doing this, it is a good time to change the filter and electrical connector. What the heck, if you are this far, might evaluate if you want to spend another $190 and replace the conductor plate which sits on top of the valve body and will be fully exposed on this job. (cheap insurance if not already done) May also want to have a spare soleniod valve laying around.

If you are a good mechanic, can keep the job surgically clean, know your way around a torque wrench, and can balance 40 lbs on your elbow, replacing the springs is not impossible.

See link http://www.benzworld.org/forums/w210-e-class/1419452-transmission-woes-dealer-needed.html
 
#9 ·
Dear Atmsmshr:

I already performed the adaptive reset and this helped only a little bit. Since I´m not an experienced mechanic I took the car to be diagnosed by the dealer last weekend and told me that the tranny is having high pressure inside and that may be some parts are already worn. Since they do not repair single parts, they just offered to change the tranny, torque converter and computer for a little over 8K! This is crazy!
I may take it to a private MB dedicated shop and see what they can find out.

Thank you for the ideas.
 
#11 ·
There are tons of threads on dealers and transmissions. Simply put, its a risky job for them to rebuild (might have an issue later), and the 8K might be "drive him away" price because they don't want to do the swap.

Look at the stickies - changing the spring adds 10 minutes to a pan pull/tranny filter change - no need to pull the valve body. But if not done the conductor plate yet on this car - as suggested - might as well do it.

FWIW - weighed the valve body - 17lbs wet.
 
#12 ·
This advice may seem controversial, however, me, I always try to find out what is faulty before attempting to fix the fault. Your issues are very difficult to diagnose. The manual list at least seven areas to look for when slippage is involved----so what!!

Most don't want to hear this but MB's have loads of diagnostic material to meet the requirement of quickly determining what is faulty. That diagnostic process in most cases is proprietary and IT COST MONEY, but sometimes the shortest distance between two points is a straight line. MY point-----get the car scanned by an independent MB guy, but make dame sure he has the diagnostic equipment, because you want to see the report before taking the next step. Don't change anything. Find out what is wrong FIRST!!
 
#13 ·
An update about this problem:

Took the car to an independent MB shop and they will check for a possible broken spring, defective conductive plate (solenoids, etc).
I should have later today more news and will update this thread.

I agree with Plutoe: I need to know what is wrong inside the transmission before doing any work on it.

Thanks for all you comments and suggestions!
 
#16 ·
Udpdated News! :thumbsup:

The mechanic confirmed yesterday that after opening the oil pan and checking the electric plate, he found the speed sensor in the electric plate damaged.
He checked the pressure regulator valve spring and was OK.
He replaced the electric plate, emptied the transmission oil left in the torque converter and refilled with new MB transmission oil, new filter, gasket and also replaced the electrical plug.
At the end of this notes I´m attaching a picture of the electric plate with the damaged speed sensor.

I´d like to thank everyone for your help and comments!

I´m not sure if going back to the dealer and ask to reimburse the $192.49 they charged me to diagnose the Tranny for just telling me that I´d needed to replace the whole transmission with the torque converter and transmission computer at a $8001.00!! :mad:

I´m tempted to write a letter to Mercedez Benz and complain the lack of professionalism that this dealer is showing when they do not take a step by step approach and just want to be a "parts swapper" dealer :twak:

Thank you again and I´ll be more than happy to answer any question.

 
#19 ·
Musikmann:

Almost an arm and a leg!

Well, it was expensive ($950.00) but not as bad as changing the transmission :crybaby2:
The mechanic I sent the car is not cheap but is quite serious and systematic when diagnosing Mercedes Benz cars and I had good references from other MB users.

I think I´ll write a serious letter to MB and see what they say about it.....
 
#18 ·
Congrats on things being fixed - and finding a knowledgeable mechanic! RE the dealer refund and letter - go for it. Your story is the same for many with dealers - not all, but many stories - and why they can have such a bad reputation.
 
#20 ·
Updated news:

After complaining with the dealer about the wrong diagnostic performed by their service team, they agreed to reimburse me the diagnostic charge. :thumbsup:

At least they were serious enough to recognize their mistake and I got my refund.
:)
 
#22 ·
Stupid question but does this reset for the transmission thing, clear the codes on the trans without the star diagnostic system? For example, If my car went into electronic limp mode as they call it, can I reset the trans computer, by doing this adaptive learning thing. Or is this only a feature? I know my regular OBD II scanner won't clear the underlying codes.
 
#23 ·
Nope.

The reset being discussed is the adaptive shift points that the TCU learns (and adapts to) as you drive. Resetting just puts them back to a baseline.

The only way to clear the codes is with a proper scanner connected through the 38-pin diag port under the hood. SDS, Carsoft, Snap-On, etc.

However, simply because you are in limp mode does not mean you have one of the hard codes that needs to be reset (it depends on why it went into limp mode). Fix the underlying problem and see if the limp mode is fixed, if not go get them cleared.

Good luck.


PS: Please click user cp and add your vehicle and location to your profile, it's useful information going forward.
 
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