SirHiss05

Greetings friends. I have researched this extensively and while some posts describe some of my problems, no posts have all of them so far. Please help. First time MB owner and first time poster though I have been reading for years.

2006 S65 AMG with 71500mi. (Just got it 3 weeks ago.)
Mods: Eurocharged TCU and ECU upgrade tune. Installed 1500 miles ago, no issues when installed. I drive it easy and don't beat on it.

Symptoms:

Driving for about 30 mins at highway speeds and car drops out of gear. Slips with no response like its in neutral but still selected in gear. High pitched whine (fairly quiet) and it is RPM responsive. Higher RPMs = higher whine. Trans drags enough to move it at low RPM in first gear while slipping. Will not shift and slips badly. Eventually wont move at all, totally slipping. Selected neutral then drive, will not engage in gear. Turn car off to reset and restart. Will engage in gear but slips immediately. Limped it home, (5 miles). Let it sit overnight and added 1/2 L of MB trans fluid. Started next morning and it engaged solidly in gear and shifted fine. No noise or whine. Rolled it on hard and it held tight in all gears. 30 mins later, exact same symptoms. Popped out of gear and slipped very badly. Whine is back. Limped it home again, parked car and no more time on it till I figure out what is going on.

Current research: Trans pan and tray are DRY. No fluid on TCU or wiring harness either. Car has had trans serviced by MB at 55000 miles.

I would like some input. Are these symptoms indicative of conductor plate failure? Filter clogged? Other potential issues? Please advise.

Skill level: Semi-pro/general knowledge expert. Have rebuild engine, trans, rear end, cam upgrade, electronics work, etc on other makes. (Not very much MB specific knowledge)

Thank you very much for your help guys!

Welwynnick

First thing with transmission problems is to check the fluid level (fully warmed up, with the engine running in neutral). Everyone says they're sensitive to fluid type and level.

You will need to buy a dipstick tool.

Nick

SirHiss05

Checked fluid level. Added 1/2 L. No change in symptoms.

Flight Test

My first guess is one of the pressure solenoids in the valve body are going bad but that is just a guess. What color was the fluid? Did it look burned?

SirHiss05

Thank you all for the responses and suggestions. As we all know, more info = more solutions. Here is the update:

Took the S65 to MB in Fredericksburg, VA and they ran a diagnostic on it. Here are the codes I am getting from the trans:

P2500 Impermissible ratio.
P2560 Implausible or slipping.
P220A Speed comparison is implausible.
p2562 Implausible or slipping.
P2561 Implausible or slipping.
p2563 Implausible or slipping.

Fluid looked slightly burned but not scorched. Have not pulled the pan off to check for metal shavings yet. Will do that this weekend.
Based on these codes, anyone have any other suggestions?

czum09

No doubt first thing I would do, is change fluid and filter.

Welwynnick

Can you describe EXACTLY what you did to check the fluid level? All the details. I've been through something similar to you.

Nick

SirHiss05

Ok, another update. Thank you again for the help. I have some more info.

Pulled the trans pan off and pulled the filter.

First off, what is the capacity of the trans and system? I only drained about 2 quarts from the pan alone? The fluid level looked good when I checked it and the trans pan and bell housing are DRY.

The fluid is def burned. In the filter and pan there is a very SMALL amount of fine metal powder. Less than a pinch between your fingers in both the filter and the pan combined. The trans has never been flushed before and there is 71000 miles on it. Is this normal wear or something more? Where would this fine particulate be coming from? Should I still be looking at the conductor plate? My plan at this point is to flush and clean the whole system, put a new conductor plate on it, new filter, new gasket and so on and button it back up with fresh fluid.

Please advise course of action or possibility of repair via the steps I have listed.

Thank you very much guys!

Welwynnick

When something goes wrong, its usually the simplest thing rather than the most complicated. Usually, not always. The simplest things are also the easiest to eliminate. In your case, the most likely explanation is low oil level. Until that is eliminated, there's not much point looking for more difficult things.

I asked how you measured the oil level, and that's really important.
Did you first warm the transmission by driving fast for 20-30 miles?
Did you check that the car was on level ground - ie: visually level, and won't roll in neutral with brake off?
Did you use a mercedes transmission dipstick tool - the one with the 20C & 80C markings, and sticks out of the dipstick hole when fully inserted?
Did you check the level with the engine running or the engine stopped?
Were you in P, R, N or D?

Everything you described when removing the pan sounds completely normal, except we have to bottom out the fluid level before looking at anything else.

Nick

shardul

iTrader: (1)

i had the same issue with my car a couple of years ago. I changed the conductor plate / check fluid etc etc and it did not help at all. Finally I just did a rebuild on the transmission and the problem was solved.

biker349

any updates?

benzct

Had the same issue on my benz. After oil and filter change, new conductor plate still no joy. Eventually after much tinkering i found the vavle body bolts not loose but not tight. Slackened off all bolts and re torqued. Problem solved and going 30000k's strong. Not sure if this could be your issue but maybe it helps.

akmatic63

My car is currently in the shop (See my thread) similar issues, turned out to be a fluid leak at the front pump

Colin Frolick

Pretty much the same thing happened to my S600 at about that mileage. Slipping, limp modes, tow ride home... speed error codes, smoked fluid, pan full of clutch dust. Took the trans apart and replaced the clutches, good to go.