Merc63

I've been experiencing a weird shift into 4th gear lately with my Weistec bullet proof tranny.

It has about 26,000km on it now.


The issue comes and goes, one day it did it all day long, only in manual mode does it do this. Sport it shifts fine every time.

So sometimes under a heavy part throttle load around 4000rpm and lots under a WOT high rpm shift, it will cut power shift and apply power again.

I know the throttles are closing to cut power because I can hear a boost bleed off as it shifts.

Has anyone else with this tranny experienced this? I emailed Weistec asking, waiting on a reply, but thought I would check on here to see if anyone else knew what was up. I'm going to try clear the tranny adaptation today. I did a fluid and filter change the other week, the old fluid was still a good red color.

Mort

Are you experiencing any wheel spin when it cuts power before shifting. My 2010 would do that exact thing if the rear wheels were spinning. It was on the 1-> 2 shift but the same scenario. If I was in S1 and let it spin to the red line it would cut power and the revs would drop to 4500 rpm and it would shift. I don't know if that helps at all but it sounds like the circumstances are causing the transmission to protect itself during the shift.

Maybe you need new or grippier rear tires..LOL

odonnks

As Mort was saying, could traction control be causing this?

Merc63

I never drive with traction control on, I forgot to mention that.


It will spin first to second shift like crazy, third gear doesn't spin, but it's been cutting between 3-4 shift... Rather annoying.

It's never really done this before so something is going on.

mr747

hrmmmm maybe the clutches are wearing again??
you wont get a answer from them until tuesday
I was made aware that wont be working

i hope its nothing for you

they now have a version 2 of the bullet proof tranny
maybe this is the fix

see what they say

Merc63

Oh a version 2 that is reassuring lol, thought this one I bought is bullet proof?

I dunno if it's slipping maybe it is and the computer detects it and cuts power?

When the tranny was slipping before it was built, it would blow through 3rd gear to redline with the car barely moving... It didn't cut power then.

mr747

Hrmmmm im not 100% sure bud

that exactly how mine was it was even popping out of drive and into N
The actual car would stop lol

just wait till they come on line and get confirmation from them

mthis

I had a issue like that driving 70-80mph 4-5gear not going wot but part throttle in M mode. my issue was tuning did some logs and sent them to my tuner and when i got new tunes it went away.

Merc63

Tuning of the Ecu or tcu?

Any idea what was changed or what the logs showed or what I should be looking for?

alpha26

Try to do a clutch relearn it might help !!!

mthis

Ecu tuning.

no idea. was long time ago. but i do have a extra ecu that might have the old tune in it so i can check that one if it does it or not.

Merc63

How is this done exactly?

odonnks

https://mbworld.org/forums/c63-amg-w204/453828-mct-tcu-reset.html

PetroC63

When was the last time you did a fluid and filter swap?

Jasonoff

The other week...

PetroC63

My bad. lol

Merc63

I talked to Weistec, they said I need to try do an adaptation thingy with xentry. My friend has the laptop, I will try it and report back. I don't think its slipping because sport mode shifts fine.

mr747

Let me know how you go I will do the same

Merc63

Well I did the adaption, which was rather difficult to hold it within that torque spec for the shift.

I did 7 adaptations for the 3-4 shift in C mode with esp on. No change in the M mode 3-4 shift, it's still cutting power for the shift.

Not sure what to do next? It's very weird how it's shifts perfect in S mode, but M it does this...

mr747

im also going to do the re-adaptions tomorrow i will let you know how i go

but i dont have your probelm

HBC350

Just an example of why I keep the important stuff stock. Flame away.

Petakii63

Why would you need to do an adaption reset when it only occurs in Manuel mode? I doubt it's the tune because he would have the problem from day one and it wouldn't randomly happen 16000 miles later. I have a strong bet his torque converter has taken quite a beating or the torque converter solenoid is failing.

Merc63

Why would you say the torque converter?

Petakii63

Because you drag race your car and that puts a **** ton of stress on TC. I'm sure your still running the stock one even if you have the Weistec upgraded trans. Don't forget your cars torque is not as linear as an N/A application so there's a lot more stress on it. Like I said it could also just be a failing sensor

roadtalontsi

what are you adaptation fill times at for the 3-4 shift. The strangest part of this is that it's only in manual mode. I dont really have any good suggestions other than pull the valve body out and check for clogs and crap build up on the screens of the shift solenoids. make sure the fluid level is correct. How long has this been occuring - is it only since you serviced it a week or so ago? post a video of what its doing.