The title says it all - definite transmission slip after going to a stage 1 tune. Feels like a torque converter car (it actually now feels just like my old E55 that was making similar power) - under load revs will build a bit until the car catches up. Happens in every gear as far as I can tell - most noticeable after 2-3 shift under moderate throttle but I can put it in 6th or 5th on the freeway and get revs to climb then fall back down. Shifts themselves feel fine, engine is smooth and very strong. Have done the adaptation reset w/ the key, and battery unplug - no change.

Car was bone stock it's whole life prior as far as I could tell, and I didn't notice any slipping (but I am not the original owner - no idea how it was driven for it's first 50k miles). 75k on it now.

Trans fluid and filter was done ~10k miles ago, I could rack it up and do another level check, but I have no leaks, it's been shifting fine, I doubt I would find it noticeably low.

Here are my questions:
1) Is it at all possible that something done incorrectly on the tune could cause this issue? As far as my understanding of a stage 1 tune goes it's mostly just increasing boost and fuel tables. I have no other mods. Transmission is slipping w/ traction on and also when completely off, doesn't feel like a 'protection mode' kind of situation. Tuner is NOT one of the 'well-known' options we see discussed on here a lot, but they are reputable and not some fly by night operation. They do a lot of Mercedes, but they do more BMW than AMG. I haven't talked with them yet, wanted a little more info before doing so as the engine feels amazing and I don't want to throw them under the bus for a good strong tune that might just be showing off a beat up transmission.

2) Given it's occurring in all gears, I would be looking at a complete rebuild. I understand the general layout of different clutches inside, but this is my first auto transmission performance car in 20 years (besides SUVs) and I'm just not that familiar with them in general. Manuals are SO much simpler! I do a lot of my own work, have a lift at home, but I think this is one I'd have a shop do. Not necessarily because of the mechanics but all of the adaptation things needed after. I'd have them do a pre-diagnostic first of course, but assuming I'd need clutches it looks like my options are Exedy ($1800ish), Blackboost ($2600), or a 'built' 722.9 from Southern Hot Rod ($5k). Assuming I find a competent mechanic, getting the clutch kits seems like a pretty easy solution. However, the built transmissions mention things like machined pistons and stronger orings, which I don't see mentioned in the clutch/rebuild kits.

Any thoughts welcomed!

 

First let's go back to stock and repeat Wot and various aggressive acceleration patterns and see what's what. It could be the tune. The trans should slip in stock ecu scenario under WOT if there is a trans issue

your mct could be dodgy too - would explain the "all gears thing"

is it slipping in comfort transmission mode as well?

No one touched the tcu right? Line pressures etc?

this guy had trans service and reset and it was resolved:
https://mbworld.org/forums/w212-amg/...need-help.html

 

I wish switching was easy, I had to mail the ECU for bench flash. I can do it again, I'd just like to know if a tune could even cause this.

TCU is bone stock. Yes happens in all modes (C, S, M, traction on, sport, off etc). It really feels just like a manual transmission with a clutch starting to go which does make me wonder about the MCT. If the transmission is coming out, I'd want to do the whole job though vs MCT repair and then find out later the gear clutches are worn too..

Mine doesn't struggle, bang into gear like that thread you mentioned, and his car seems to be stock. It just seems like too easy of a solution w/ 10k on my trans service and perfect behavior prior to adding another 200 ft lbs of torque. I did the service and checked the fluid level twice, so the chances of it not being good are extremely low (No one's perfect, but I used a scan tool and a thermal gun to set the level properly).

The other thing in the back of my mind is that, while stock, I would have days where the car seemed a little lower on power. Not misfiring/running badly, but like a heat soaked engine. I'm in a cold climate but am in a lot of traffic, so I always attributed it to those particular instances. But I wonder if I had some slight slip going on that I just didn't notice. We had that thread recently complaining about the juddery MCT...mine has always been really smooth, I've never had to 'drive around it'. Makes me wonder..

 

Also, now that it's slipping, I'm in a chicken or the egg scenario. If it's damaged the clutches, I send the ECU back for a flash to stock, reinstall and test to find it still slipping. Did the tune exaggerate an underlying issue that was already there? Or did the tune cause a problem that wasn't there, but has now damaged said clutches?

 

No reasonable stage 1 tune will damage the clutch packs this quickly unless you're outright abusing the car.

if the trans was going and this tune pushed it along then you needed to maintain the trans health anyways ... the time has come

it still could be something in the tune though I don't recall this being even a remote or rare issue after a stage 1 tune for people. And I've read a lot of threads on tuning the e63

 

As Peter stated, a stage one tune will not damage the transmission. It’s just showing it’s weak points. The tuner could lower the torque values, though the transmission will still need attention sometime in the future. I feel the same with my p30 car, eventually those clutches need to be replaced even though no additional tune has been done. A tcu tune may get you by for a bit with increased pressures but worn clutch is still a worn clutch.

Keep us updated as I know you will. I’m very interested in how diy able this is if just replacing clutches. Videos make it seem possible but extremely difficult without a light.

 

Read this

https://mbworld.org/forums/c63-amg-w...box-issue.html

 

I did see that one, but leaves me with more questions. OP never posted his solution, and others who chimed in either had the issue pre-tune or had bucking/driveability problems and mine is smooth as butter. The M156 engines are also so different being N/A, I suspect it may be more of an issue on that platform since tuning for more power without boost it makes sense for tuners to mess w/ torque tables.

I did leave a message for my tuner to get his opinion, I'm definitely not the first M157 they've tuned so I'll see what he has to say. If he offers to flash back (and then back again) for free I'll eat $30 of postage just to try, but my gut tells me this is a problem that was subtle before and now more apparent w/ more power.

 

I had a built 722.9 from Southern Hot Rod installed by EC ATX. It didn't downshift correctly into 4th gear, which is the normal highway passing gear, if you were on the gas at all. I had several places look at it (MB dealers, transmission shops) and nobody could tell why it was having the issue. I got a new valve body from MB, and it didn't help. I ended up trashing the SHR tranny and got a used transmission from ebay rebuilt at a transmission shop and it has since worked fine. It wasn't really safe for someone to rebuild the SHR transmission because it wasn't clear where the problem was. I easily wasted over $10k on the SHR & inspections, not counting the later rebuild. I have heard from others of similar problems on m157 cars, but also apparently sometimes they work fine. I don't know if they have QC issues or what, but I wouldn't recommend.

 

Good to know! I've heard mixed things as well - I'm not the biggest fan of Raybestos which is what they use for the clutch material supplier. I sent a message to Blackboost a few days ago with some questions about their clutch kit, but so far no response...

Getting an Ebay trans is tempting though, then I could take my time rebuilding.

 

Not sure if these people can help, but might be worth making a call.

https://fdt-online.com/722-9.html

 

Update: Because I already had a jug of transmission fluid in the garage, I went forward with doing a flush yesterday just to rule out the 'cheapest fix'. Drained the fluid and it was really clean, still blue and no burnt smell so I opted against messing with the return line and messy job of a full flush.

Measured what I took out - just under 5L. Replaced filter (Genuine) etc, pumped in 6L. Ran to 45 deg and set the level. About 1L came back out. So, no red flags there.

Here's where things get weird - at first, it was better! The slipping had gotten really bad, I could feel it at under 20% throttle. Now it seemed to hold and I thought it was fixed. Shifting was a bit rough at times so I did the pedal/learning reset. After a day of driving, it's still much improved but it WILL slip when starting in comfort and giving it 40-50% throttle.

The shift pattern is also very different (even after reset and driving it somewhat aggressively) - it shifts like a diesel. Unless I'm really on it, it will shift as soon as humanly possible. Even in sport mode it will put itself in 6th gear at 38mph and only downshift when rpms fall below 800-1000 and won't downshift unless I stab the throttle. So it feels like it's lugging around constantly.

The TCU is inside the transmission on our cars correct? I'm wondering if the fluid change 'helping' was more a product of having to unplug the wire harness to remove the pan and powering down the TCU.

Still no fault codes. I think my next step is to have the dealer run it through tests and update software. I think I just won't mention the stage 1 tune, less likely to get a grumpy tech who won't spend the time diagnosing things on a car that isn't stock. We'll see what they say about the oil solenoid and IC pump codes though haha.

 

Dealer ran diagnostics, found most of the adaptations are out and are recommending a new transmission. I considered my options and am having them go ahead with it. My only other options were trying a used one (harder to find the awd but there are a couple), however making time to do the repair and the risk of it also having unknown internal wear makes it not seem worth it. I could also get HD clutch packs and rebuild, but adding more modifications comes w/ headaches, and BlackBoost said I would need TCU tuning on top of dealer adaptation etc etc and I don't plan on modifying further than the stage 1 ECU tune.

Dealer has to adapt it regardless, so they'll get it done with a new unit and I should (hopefully) be good for a long time.

But I will say - let this potentially be a warning to those adding more power, it clearly illuminated existing wear in the transmission on a car that, to my knowledge, has been stock since new. I drive it aggressively but not HARD (i.e. drag launches etc), but of course I don't know how the original owner treated her.

Onwards and upwards!

 

I'm glad you've come to a resolution but does this COMPLETELY rule out your tune not being corrupt or bad???

 

I don't see how it could - transmission clutch fill times are their own thing, no way an ECU tune could cause issue with those as far as I understand. Tuner has done a lot of these cars too without issue.

They'll adapt the new clutches and if for some reason it won't take them, then we can discuss flashing stock software back on it.

 

why does this smell like a dairy farm in the Spring?

you know, there is an adaptation procedure using Xentry that resets and readapts the tranny? It takes two Germans in white labcoats to run it, but it is part of the diagnostics process. Search YouTube to see how it is performed. How much do they plan to charge for the new tranny?

By the way, growing up in south Florida, there was a time when cars didn’t have A/C. But they did have those funny little vent windows next to the A pillars.

 

Yes, and I believe they attempted some re-adaptation, but the values were still way out. Which doesn't surprise me, the slipping had gotten bad enough that I could feel the engine rev up going up a slight hill at 10mph. It's more than just needing Xentry adaptations to fix it unfortunately. Also explains why a battery-off hard reset did improve things for a time, but they kept getting worse after that. The job is under $10k after tax....but not by a LOT...

 

Ouch!

 

Update! Car is back from the dealer, new transmission and MCT unit, driving fantastic again (no change to tune).

So - let this be something to add to the 'I want to buy an E63, what should I look out for?' things to check. Get a PPI with a shop that can scan transmission adaptations w/ xentry, maybe I would have had some warning of clutches wearing if the previous owner beat on it or had it modified (although there were no signs, even when I took downpipes off for motor mounts the bolts still had factory paint markings etc). 75k miles, I had it from around 50k.

 

Post #40 in the Ultimate Thread is this thread .. glad you're back to good

 

Curious, but what did it cost you in the end?

 

10k w/ tax

 

well worth it - it's a great car - even greater when tuned

 

Well, I'm back with a not-so-great update, could really use some fresh perspectives. After the transmission work I reverted back to stock (tuner refunded me) and things were fine. I went through everything with a fine toothed comb as I still had a slight 'bounce' in rpm when accelerating from a cruising speed in a fixed gear. It felt like a vacuum leak to me, sure enough it was, a slight leak around the MAP sensor oring that is now fixed (confirmed w/ smoke testing). Car felt really good, smooth power and shifting was on point. Dragy has me at around 3.8 sec 0-60 which is ok, I thought maybe it should be a few tenths quicker but to me didn't indicate a huge problem (I haven't had room for 60-130 or 1/4). No codes. Logging MAP readings only shows 11 psi (adjusted, actual reading 176 kpa at sea level) in 3rd gear on those runs. Seemed low but did also find other threads mentioning that might be normal. Shifting crisp and great.

So, I deemed it healthy, and purchased an EC tune from Jerry who after hearing my story with the last tune told me he'd honor a refund if the same problem happens again. Loaded it this morning, car made crazy good power for 5-10 minutes, then went back into a kind of limp mode with rpms seeming to slip (keep in mind transmission and MCT are new). It's not slipping like it did before on my old transmission, but it's definitely cutting boost and power.

Vacuum lines all hold vacuum and wastegates move, vacuum check valve good. No codes. Plugs (OEM and gapped to .24) and coils all less than 5k miles. Cleaned air filter MAPs. Swapped main MAP and boost control solenoid from our GL63, no change. Cam sensors all dry along with ECU harness.

I find it very hard to believe 2 tunes have the same issue on a stock car, the first tuner didn't have a lot of these cars under his belt but EC does. I emailed Jerry to see what he thinks, but wanted to post this here while I wait to see if anyone else has any ideas before I tear my nonexistent hair out. The next thing I'm trying to do is get a hold of Xentry to look at individual cylinders for misfires, although it seems unlikely a problem this apparent wouldn't be throwing a code. The fact that the car doesn't shake or buck when this happens tells me it's disengaging the MCT, right? Why?!

Here is a video- accelerating steadily and 'normally' (20% throttle?) from a stop in C. You can see it bump up once in 2nd, and then do 2 slips/rpm raises in 3rd gear before shifting again.

 

Did you send the logs to Jerry. He's legendary and he will dial this in or at least give you top 3 causes of this now that he's on the case.

it drove fine with perfect shifting for 10 minutes after loading the tune?

And it still drives and shifts fine when going back to stock?

Would love to see a log of the boost, IAT's, fuel trims, wastegate during a hard pull with the tune file loaded

Fuel .... did you replace fuel pumps? I forget
... check out this thread
https://mbworld.org/forums/w212-amg/...situation.html