skylinrcr01

morning all,

This morning on my way to work, I had my transmission pop out of third when I went to pass someone. (In other words at hammer down, full throttle) It made a loud clunk, sounded like something slammed into something else and then the engine free revved. I tried using the paddles to shift into another gear, but the transmission just stayed in 'c' mode. Then I pulled over and restarted the car, and everything works fine again.

Did a couple pulls on the freeway from 40-80 like I did before and nothing weird happened.

Any ideas what could have caused this? Conductor plate? Clutch pack? Fluid level?

BoostedAero

Check fluid level then if its off correct it... more than likely the conductor plate is failing ( I hope ) or you may be looking for a complete rebuild

k2 was the most strained clutch in 3rd and usually wears the worst and is the first clutch to fail from what I have seen.

Anychance you can see fill times/pressures in SDS?

skylinrcr01

Not yet, I'll scan it when I get home though.

Would that be under actual values in the transmission controller?

BoostedAero

From memory (forgive me)

Control units
Drive
Transmission
--->Read Fault codes and document they will tell you what stored
Adaptations
Read or reset adaptation values

Then read each one or all

3-4 and 4-3 are going to be the most important in this case


IDK why I make this hard on myself

Barry put in all the work...Thanks BBirdwell!

https://mbworld.org/forums/w211-amg/...rmination.html

skylinrcr01

Much appreciated. I'll run it tonight, me and my wallet hope it's just the stupid conductor plate too, car only has 89K miles.

BoostedAero

From Barry's thread:

"I only found out when I had it cut out after a high speed overtake. Went out of gear, no CEL, was fine when car restarted. Did it once more and I took it to the dealer and they gave me all the info above and identified K2 clutch as slipping. Code was for inappropriate gear ratio."

Good luck my friend 89k isnt bad but the SDS system will tell all it seems

skylinrcr01

So the code was stored as P2500, impermissible ratio.

Looks like the packs are ok though, which is a huge relief. 4-3 is 3 and 4 cycles, and 3-4 is 4 and 3. Which sounds confusing when written out, but hey, that's the data.

tw2

This was me. If you got impermissible gear ratio I would say it has to mean something is slipping. Mine was 3rd to 4th WOT. Restarted the car and back in gear again. I checked fluid, all fine, replaced the conductor plate hoping it was that, it wasn't. Full rebuild later...

skylinrcr01

I'm really hoping that's not it, but if it is it is.

Just checked the fluid, and was 1/2 a qt low, so I added some. Fluid looked otherwise clean.

MACEDON

How the hell

what happened to your fluid...

skylinrcr01

No idea, maybe I have a small leak somewhere, 1/2 quart isn't a ton. Could be that connector on the side, haven't had a chance to look at it yet.

This is by far and away the scariest problem this car has had thus far.