722.6 automatic trans - PeachParts Mercedes-Benz Forum

alphanumeric · #1 02-11-2011, 03:38 AM

the 722.6 is said to be a tough transmission. so far it has been, until!

car is 2000 w202 c230 Sport Kompressor with 130-140k miles. new Maf and O2's.

after reading many post.. about k1 springs, faulty shift lever linkage module etc etc etc... I have more symptoms then just being stuck in 1st\2nd gear. note: car is always in Drive and in Sport mode aka 1st gear start.

I will have to update this post when I can drive the car again to see if its 1st or 2nd gear it starts off in, and stays in.

1st- 10% of the time, transmission works fine, shifting thru all gears, on a cold start up.

2nd- 90% of the time on a cold start it is stuck in 1st\2nd gear.

3rd- when I put the key in ignition and try to take it out of park, it hesitates like its locked in park. 5 years ago I did spill a drink in the shifter and it locked into Park. I pulled that lever as hard as I could to put it in Drive. I think I semi broke that lock, but non the less, 5 min later after turning the car off\on it worked fine ever since! but now, if memory serves me right, I am able to shift the car from neutral to drive, or park to drive w\o pressing on the brakes.

4th- when the trans is stuck in 1st or 2nd gear, it makes a whining noise. sounds faint. the whine noise will not be there when it shifts normal. only when its stuck in 1st or 2nd.

5th- Many months ago, one of the first symptoms of my failing transmission was on a cold start, at the first red light I would come to, when light turns green, I accelerate, but car starts off in 2nd gear, then jambs itself into 1st gear harshly at 5-7mph, then 2nd,3rd,4th,5th shift was all normal. and would be fine for the rest of the day. happened almost daily on cold start.

6th- many months ago, just one random morning, I started my car and it was all fine for about 30min of driving until I was stuck in 4rd gear! I pulled over and turned car off\on and it was fine, then I was stuck in 2nd gear and could not go faster then 45mph. I heard that same whining noise coming from transmission, next day and months, it ran perfect!

7th- I replaced trans oil, filter, seal and the Electronic plastic plug\port & seal that is common to leak from. car was fine until!!!!!!

8th- I was being dumb with my daily driver in the rain with ESP off, breaking the rears loose and getting side ways on the curves. it was all good until the next day, trans started getting stuck in 1st\2nd gear with the whining sounds.

another little random note. I think, when the car randomly will drive and shift through all gears fine, putting the shift lever from Park to Drive will not hesitate. but after a few test runs, the car will always revert into being stuck in low 1st or 2nd gear.

thanks for any helpful ideas!

whunter · #2 02-11-2011, 11:30 AM

Sounds like it is locked in safe mode.

What are the codes?

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alphanumeric · #3 02-11-2011, 05:17 PM

zero check engine lights from the obd2 =\

after sleeping on it, I am thinking its something electrical and not mechanical

Gilly · #4 02-11-2011, 07:19 PM

"S" is not sport mode, it is "standard" or 2nd gear start.

alphanumeric · #5 02-11-2011, 11:29 PM

I always thought it was "sport" and "winter" S\W

so if S is standard, what is W?

alphanumeric · #6 02-11-2011, 11:33 PM

I found a 97 or 98 C230 kompressor at the junk yard 240k miles!!!. I am thinking of pulling some transmission electronics from the car just to swap into my car to fix the problem, only problem is... how many electrical components consist of the transmission? and locations of these devices.

whunter · #7 02-12-2011, 12:29 AM

Quote:

Originally Posted by alphanumeric

zero check engine lights from the obd2 =\

after sleeping on it, I am thinking its something electrical and not mechanical

The transmission codes are not OBDII = have it scanned at the dealer with the STAR diagnostic tool.

alphanumeric · #8 02-12-2011, 12:36 AM

ahh that sounds like a plan, thanks very much! dont you just hate taking your car to the dealer... what else can ya do

Ferdman · #9 02-12-2011, 05:57 AM

W is Winter. Read your Owner's Manual for an explanation of the different modes.

alphanumeric · #10 02-12-2011, 07:22 PM

I def understand the two modes, was just not familiar with the correct term for them.

I will revive this post at a later date when I figure out what was wrong with the transmission. I found another thread on benzworld, they talk about maybe some fluid leaking into the harness and into the controller.

whunter · #11 02-12-2011, 10:40 PM

Quote:

Originally Posted by alphanumeric

I def understand the two modes, was just not familiar with the correct term for them.

I will revive this post at a later date when I figure out what was wrong with the transmission. I found another thread on benzworld, they talk about maybe some fluid leaking into the harness and into the controller.

Here is what they are talking about, it is a common issue.

2035400253 Transmission Electrical Connection Spacer
2035400253 Transmission Electrical Connection Spacer

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daddi · #12 02-14-2011, 12:46 PM

Try opening the computer box and disconnecting the computer for the transmission and turn it upside down, if you get transmission fluid leaking from it you've found your problem.

alphanumeric · #13 02-14-2011, 03:23 PM

thanks guys. I will be doing this real soon.

I cant believe how reliable and strong the 722.6 transmission is. I just cant understand why all the w202 c43 amg owners on Club202.com were having to have their transmissions rebuilt under 100k miles!

DRBC43AMG · #14 02-15-2011, 05:42 PM

Probably because they drove like cowboys

alphanumeric · #15 06-14-2011, 03:45 PM

well, i thought i would do a fallow up like I said.

car is now fixed and it was pretty easy.

I did in fact take the car to the dealer so they can read codes. service adviser told me codes came up for shift lever module, brake light switch, and the conductor plate inside the belly of the transmission.

they then reset the codes and the only thing that showed now was shift lever module. 1300$ from dealer!! so I shopped around online and let me tell you.. the shift lever module is a anti theft part.. so I would have to be there in person with the title of the car to buy this part. I actually got the run around buying one, it never shipped. I called over and over again and was put on hold and they said they would call me back for a week!.. eventually I found another shop online and paid 500 for it. I left my car at dealer for almost 3 weeks and they were fine with it. I picked up my car.. drove it 1 block from dealer in 1st-2nd gear. pulled into a parking lot and swapped it out in 20min, and vuala. it feels like I just bought the car all over again.

while the car was at teh dealer, I did have them install new brake switch for 145$ to compensate for the cost of the star diagnostic test.

now I am fighting the dealer so they can refund me another 145$ they charged me for unautherized work done, they went ahead and put a new shifter bushing on my lever! which does not make any sense cause the new shift lever module came with one!

hope this helps some of you guys out..

next I will be replacing the trans conductor plate.. I think they are 150$, might as well... right?