Have a 97 722.6 transmission that has an intermittent problem. Seems like its under cornering and hard acceleration the car seems like it goes into neutral even though its in gear. trans fluid level seems correct. Read about a freewheel issue with these early transmissions in some other posts. Is this part of the valve body. so in other words if I were to order the valve body would the freewheels be part of that? Or do you guys think it could be related to something else?


thanks

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CR

Bump, sorry.....

Hello crconsulting,
early .6 AT really had a problem with the F2 Free wheel unit- in particular in Mod 163. The symptoms match. The F2 is renewed along with the sungear assy. and the job is (once you have the AT on the stand) rather an easy one.
However, I must say that before you go into that job, replace the so called "electric kit" on top of the valve body. It's the black plastic frame holding the solenoids. Early ones had non insulated circuit boards and loved to shorten out by metallic debris and dust. Symptoms then were similar.
Have the DTC read out in any event!
All the best,
Dokta

That is a classic symptom of being low on fluid. Any other drivability problems. Does the transmission go into limp mode when it slips? Any transmission codes in the system.

Thanks for the reply's.

Fluid level was the first thing I checked. Fluid level seems correct. Pushed the special tool (dipstick) in till it bottomed out and checked the fluid. On a flat surface of course. trans was at least 80 degrees.

I did replace the filter recently though????

No limp mode. as soon as I slow down the transmission "catches" and continues normally. I'll see if it triggered any codes
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CR

My 97 E320 has the same malady. When you coast up to a, right turn yield , situation and feed in the throttle it will freewheel and then engage hard with a bang. Seems more on right turns than left.
Fluid level was fine, I changed fluid and filter ( proper fluid , checked level hot and cold) same problem. This transmission also will freely rev about 3-500 RPM at the top of a hard 2nd gear pull , and then bump back into engagement.
When it is driven very conservatively it shifts fine, and except for the top of second it can be matted and accelerate perfectly.
Sympathetic MB tech put it on the computer...no codes. He said that he had not seen a bad conductor plate without a code. I did have fluid in the plug, and I changed the adapter plug.
Is this the early trans symptom and does it take a valve body or can the ETC change things.
I have 166.500 miles of which I have driven 36,000 ....seems like it won't break it, but I would love to have a solid second gear.

Jeff

__________________
Jeff

97 E320, ours 217,000miles
91 190E 2.6 daily driver 242,000miles
74 MGB,mine 120,000?
2006 BE350/Proline 21, 50 hours

After doing a little investigative work and help from this board. Turns out the freewheel units or spags are in the front of the transmission so replacement requires removing transmission (Joy!) It sounds like your car is worse than mine, but symptoms are very close. Once it slips, mine wont re-engage till I come to a full stop. no harsh re-engagement but not very fun either way. I really have to push the car pretty good to get it to slip though. and yes right turns seem worse, odd......

I'll post a picture of the freewheel units if I can find the picture again.

I havent done the valve body on mine either, I wonder if there are different part numbers for different cars or is it one valve body part number for all 722.6's. I have access to a 722.6 for parts but am not sure if the part number is on the valve body somewhere to check if it's the latest revision.

And what about ECU's car specific also or one standard unit programed for a specific car model SL600 in my case.....

Just wanted to chime in and say this thread was very informative for my situation. I have a 1997 C36 which has the same symptoms as described here to the T. I also find it most prone when taking sharp right-hand turns. Tranny appears to stick in freewheel mode (with the engine revs redlining) until I come to a stop. Then without any drama the transmission appears back to normal. This has happenned twice in the past week so far. It is not happenning to often yet.

VERY unnerving.

In my case I had a prior transmission issue (73K miles) in which a clutch pack failed. I had the transmission rebuilt at that time.

Now I have this problem at 116K.

I wasn't expecting to find a thread on this as the symptoms sounded too odd to be common. Well, thank goodness I found this one!

Would anyone else have any similar experiences? Or any further advice to add for troubleshooting? I'd greatly appreciate it.

I am trying to schedule a time to have my mechanic look into this. I will show him the info in this thread. Hopefully it will help determine root cause quickly. If anything gets resolved i'll be sure to post an update.

Thanks,
Christian

My tech has seen a few bad conductor plates with no CE light and no codes. Hard to track down.

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John Shellenberg
1998 C230 "Black Betty" 240K

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