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2015 E400 currently at 104k miles. Lately I have been noticing the gear shifts can be really felt especially at first drive in the morning and also sometimes in slow traffic when car slows in traffic and picks speed. Overall it looks changing to higher gear can be quite felt. Car has no problem with engine / transmission mount problems and I can say the gear shift I feel is from transmission but not due to anything loose. It has no other issues and been serviced regularly at dealer. Is this an indication of anything that needs attention ? Also it is approaching Service A and wondering if it is good to have transmission and differential fluids changed. Thanks for your replies in advance.
2015 E400 currently at 104k miles. Lately I have been noticing the gear shifts can be really felt especially at first drive in the morning and also sometimes in slow traffic when car slows in traffic and picks speed. Overall it looks changing to higher gear can be quite felt. Car has no problem with engine / transmission mount problems and I can say the gear shift I feel is from transmission but not due to anything loose. It has no other issues and been serviced regularly at dealer. Is this an indication of anything that needs attention ? Also it is approaching Service A and wondering if it is good to have transmission and differential fluids changed. Thanks for your replies in advance.
Unfortunately this is the normal course for stock conditions.
The transmission is unable to adapt well to the hot drafty engine.
Get the tranny serviced to begin with
What/how is the history of tranny oil+filter change since 2015 ?
At the least it has to be done twice already..... was it ?
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I got it at 60k as CPO in 2020 and it wasn't done once since. Not sure if it was done before. Dealer never mentioned about the transmission fluid change so far during any of the visits.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by mbe400user
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I got it at 60k as CPO in 2020 and it wasn't done once since. Not sure if it was done before. Dealer never mentioned about the transmission fluid change so far during any of the visits.
You need to ask the dealer. If the tranny was serviced at a Mercedes dealer, it will be in the car's records.
What you are describing can likely be resolved with a tranny reset. Do a search on "transmission reset" or "hard shift". There's lots of discussion. The tranny reset needs to be done with a scanner like LAUNCH or XENTRY. Reset gear shifts only.
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I got it at 60k as CPO in 2020 and it wasn't done once since. Not sure if it was done before. Dealer never mentioned about the transmission fluid change so far during any of the visits.
Even if tranny has 1 oil + filter change, that is already 5 years ago at best.
Do a tranny oil and filter change, and being a 2014 with surely B03 start stop, you can drain the torque converter of its tranny oil by removing the AUX tranny oil pump, it is quite a lot 3.5 liters.
Thus your total tranny oil replacement would be approx 10 liters.
Genuine tranny oil filter and use the blue tranny fluid, use Fuch ATF 7134 FE is good. https://www.fuchs.com/hu/en/product/...N-ATF-7134-FE/
Let us know the result.
FYI I change my tranny oil very soon and often, within 2-3 years maximum, or 20,000KM. DIY.
Its the cheapest insurance and gives you the smoothest tranny operation as it should be.
Tranny is a hydraulic device, the oil gallery is so small for those valves doing the fine shifting of gears and their related clutches...yes lots of clutches on 7G tranny.
Thus oil cleanliness is godliness. The clutch friction material wear and tear and any other metals normal wearing is held in suspension by the tranny oil.
One can imagine the delicate duty a "hydraulic" fluid working is such filthy environment.
Last edited by S-Prihadi; Dec 10, 2024 at 09:24 AM.
Reason: ADD INFO
Even if tranny has 1 oil + filter change, that is already 5 years ago at best.
Do a tranny oil and filter change, and being a 2014 with surely B03 start stop, you can drain the torque converter of its tranny oil by removing the AUX tranny oil pump, it is quite a lot 3.5 liters.
Thus your total tranny oil replacement would be approx 10 liters.
Genuine tranny oil filter and use the blue tranny fluid, use Fuch ATF 7134 FE is good. https://www.fuchs.com/hu/en/product/...N-ATF-7134-FE/
Let us know the result.
FYI I change my tranny oil very soon and often, within 2-3 years maximum, or 20,000KM. DIY.
Its the cheapest insurance and gives you the smoothest tranny operation as it should be.
Tranny is a hydraulic device, the oil gallery is so small for those valves doing the fine shifting of gears and their related clutches...yes lots of clutches on 7G tranny.
Thus oil cleanliness is godliness. The clutch friction material wear and tear and any other metals normal wearing is held in suspension by the tranny oil.
One can imagine the delicate duty a "hydraulic" fluid working is such filthy environment.
Thanks. It is going to be a dealership visit and not sure if they also do the drain from AUX too. Torque convertor went bad and was replaced in 2022. Does this typically also include transmission fluid change ?
Wow...torque converter went bad in 2022 ?
What actually happened to TC according to MB guys ?
When TC replaced, most likely they will drain the tranny fluid as best practice.
If the TC shed its clutches material ( one of the failure mode), what you are now experiencing could be those "dirt" have traveled to sensitive zones.
I would think if and when a TC is replaced due to failure, they would at the least tear open up to the conductor plate and valve body and all the oil valves and flush the tranny oil cooler too,
to clean the shredded "dirt".
Wow...torque converter went bad in 2022 ?
What actually happened to TC according to MB guys ?
When TC replaced, most likely they will drain the tranny fluid as best practice.
If the TC shed its clutches material ( one of the failure mode), what you are now experiencing could be those "dirt" have traveled to sensitive zones.
I would think if and when a TC is replaced due to failure, they would at the least tear open up to the conductor plate and valve body and all the oil valves and flush the tranny oil cooler too,
to clean the shredded "dirt".
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Thanks for the pictures. That is some awesome info for someone like me who don't know much about what is going on there.
For the TC replacement, I experienced shudders especially around 60 - 65 mph or when starting from a stop light. They diagnosed it as bad TC and replaced when it was under warranty. Kept it for about 2 weeks mostly I guess for the part to arrive but not sure what else they did. All I see is the part number and work info on receipt.
Thanks for the pictures. That is some awesome info for someone like me who don't know much about what is going on there.
For the TC replacement, I experienced shudders especially around 60 - 65 mph or when starting from a stop light. They diagnosed it as bad TC and replaced when it was under warranty. Kept it for about 2 weeks mostly I guess for the part to arrive but not sure what else they did. All I see is the part number and work info on receipt.
Oh boy... If the TC contaminated the transmission, i.e., left debris within the transmission regardless if MB changed the oil 100 times, the original work is still pending to be fixed. Summary: I am surprised MB only changed the TC and not the whole thing: torque converter and transmission.
If a fluid drain and exchange improve it considerably, here is my summary: the remains of the original problem is still there, i.e. debris, and you may need to service that transmission more often than the manual states.
Oh boy... If the TC contaminated the transmission, i.e., left debris within the transmission regardless if MB changed the oil 100 times, the original work is still pending to be fixed. Summary: I am surprised MB only changed the TC and not the whole thing: torque converter and transmission.
If a fluid drain and exchange improve it considerably, here is my summary: the remains of the original problem is still there, i.e. debris, and you may need to service that transmission more often than the manual states.
Scary to hear what you said :-) but (luckily) didn't notice any issues so far until this hard shift issue. I'll have at least the transmission fluid done for now and see how it goes.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Get the tranny serviced, but do not dismiss the need for a reset and adaptation, which is electronic versus mechanical. I was experiencing hard downshifts from 4th to 3rd, and 3rd to 2nd. @BenzNinja effectively did a reset for me and after driving about 100 miles (to adapt), the transmission is back to smooth as ever.
The hard shifts were on my SL and developed/worsened over time. I've also had that problem with my C-Class, but it was corrected after the dealer serviced the tranny.
Last edited by JettaRed; Dec 10, 2024 at 12:30 PM.
Does it do it in echo and sport (not sure if yours has those settings)? It may need a reset like jettared suggested although I would agree with previous post they should of replaced the tranny or rebuilt it fully after the TC fiasco. Unfortunately car dealers are not the most trustworthy, even the MB ones. Ive scene them get the money for a full rebuild but only swap out parts on customers cars. Not saying thats the case but...
In my opinion I would take it back in and explain the issues and go from there. Get armed with info from the forum to help prevent the strong arming they do.
It only has Eco and Sport modes and I always drive in Eco mode. I'll try and see what the dealer say about not changing the transmission when TC was replaced.
Does it do it in echo and sport (not sure if yours has those settings)? It may need a reset like jettared suggested although I would agree with previous post they should of replaced the tranny or rebuilt it fully after the TC fiasco. Unfortunately car dealers are not the most trustworthy, even the MB ones. Ive scene them get the money for a full rebuild but only swap out parts on customers cars. Not saying thats the case but...
In my opinion I would take it back in and explain the issues and go from there. Get armed with info from the forum to help prevent the strong arming they do.
It only has Eco and Sport modes and I always drive in Eco mode. I'll try and see what the dealer say about not changing the transmission when TC was replaced.
So I got the Transmission fluid changed at a reputed MB Tech shop in NH instead of Dealer. Issue still persists even with new fluid. So I guess next step is to get the reset done too. I'll check with the shop again if they can also do the reset.
So, here's the final update. Before doing anything that involves tools, I tried the reset procedure shown in this video and could notice the difference right away.
Now, the hardest shift I can feel after this reset, which occurs in the very first drive before I reach above 20mph in the morning, is very subtle. Apart from that, I don't feel any shifts like I mentioned initially when slowing down or accelerating as it changes between 2nd and 4th gear up/down. The difference after the reset can be experienced right away and has remained the same after 200 miles so far.
I don't have much experience with 722.9 transmissions yet, but 722.6 and previous Mercedes transmissions are well known for developing hard shifts. Sometimes they go away for a while after a reset but come back, sometimes they stay gone, sometimes a reset does nothing. Sometimes they happen once every 2 months, sometimes more frequently. If you look at enough posts, you will see a lot of people saying to just deal with it. You will see hundreds of dealer visits where the dealer told the customer it's "normal". I really don't know, but I'm glad yours is doing well for now. Hopefully it stays that way.
I don't have much experience with 722.9 transmissions yet, but 722.6 and previous Mercedes transmissions are well known for developing hard shifts. Sometimes they go away for a while after a reset but come back, sometimes they stay gone, sometimes a reset does nothing. Sometimes they happen once every 2 months, sometimes more frequently. If you look at enough posts, you will see a lot of people saying to just deal with it. You will see hundreds of dealer visits where the dealer told the customer it's "normal". I really don't know, but I'm glad yours is doing well for now. Hopefully it stays that way.
It's "important but not urgent" to recognize abnormal shifts because clutch friction material is a contaminant that plug up the screens on valvebody pressure control solenoids.
The steel plate material end up on the internal magnets.... all good.
It's unfortunate the TCU does not flag poor shifts. It only faults extreme conditions for shop calls. The TCU is well aware how its shifting.
Last edited by CaliBenzDriver; Jan 4, 2025 at 02:57 PM.
Indeed. I want to watch my shift parameters live for a few weeks and try to learn something. Xentry?
I don't know what useful tranny data Xentry exposes that you can use to rate the upshifts/downshifts quality.
There are tons of variables beyond valve body clutch pressures solenoids.
The poor shifts are courtesy of the ECU not tranny itself. When ECU request an impossible shift, TCU does its best to execute.
Last edited by CaliBenzDriver; Jan 5, 2025 at 03:43 PM.
I don't know what useful tranny data Xentry exposes that you can use to rate the upshifts/downshifts quality.
There are tons of variables beyond valve body clutch pressures solenoids.
The poor shifts are courtesy of the ECU not tranny itself. When ECU request an impossible shift, TCU does its best to execute.
I would like as much data as it can provide. From as simple as a constant readout of vehicle speed, RPM, and current gear. I would also like clutch engagement times, solenoid pressures, current adaptation values, whatever information it has on the brakes, etc. I don't know what info can be passed through to Xentry, but I'm pretty sure the TCU is monitoring these things.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by ChuangTzu
I would like as much data as it can provide. From as simple as a constant readout of vehicle speed, RPM, and current gear. I would also like clutch engagement times, solenoid pressures, current adaptation values, whatever information it has on the brakes, etc. I don't know what info can be passed through to Xentry, but I'm pretty sure the TCU is monitoring these things.
If there is a sensor for something, it can be passed through XENTRY. XENTRY is the standard for Mercedes scanning and diagnosis.
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