It may just be the auxiliary battery,if not the conductor plate.easy fix with assistance

 

Duke: Thanks for the reply. My 95 Benz is too old for the auxiliary battery. Also the conductor plate is for 96 and newer 722.6 Transmissions. It is sad but I am becoming semi-expert with the 722.3 tranny. Thanks again for at least trying.

 

My '96 SL has 722.5 trany

 

Wow…I didn’t know that..I should have done more research..I just mine the day after thanksgiving,so I’m still learning and want to know as much as possible about all of them.it’s my favorite car from here on out.You’ll get yours right.Thanks

 

I had this issue in my 2000 W208.
But that's probably a different transmission + Steptronic system.
But the symptoms were identical to yours.

The problem was the conductor plates because liquid got into the shifter boot and caused this issue during cleaning.
Fortunately for me, they were able to replace the shifter with another one and all is good now.

Just sharing experience. Hope it helps,

 

BRN thanks. I think it is something fairly simple. I just have to find it. The good thing is it is drivable as I only drive 10 minutes to work and never over 30 mph.

 

My tranny won’t upshift and now starts in 1st gear where it previously started in 2nd.

wplaine_95 I was having this same exact problem with my 91 500sl. It was working fine and I cleaned the injectors and the it started doing the same thing you described. The giveaway was it starting in first gear! I went back and removed the air cleaner box and started looking and there on the passenger side rear of the engine is a vacuum line that goes over the injector hold down bracket. It was not plugged onto the port. I had unplugged it to remove the injectors and had not reconnected it. OK now. I've learned between the injector problem I had (see my post, undriveable when warmed up) and now this, stop and think "what was the LAST THING I did before the problem started
and 9 times out of 10, you'll find the issue. I missed that one because it was sitting on the manifold in front of the metal tube it plugs onto and it looked like it was connected.

 

I have had the air cleaner box off numerous times looking for issues. Thanks for the suggestion I will definitely look at that tomorrow and let you know the outcome. I pulled the governor last week but it was working fine and didn't look gummed up. So under the hood I go!

 

First and foremost, are you starting in first gear? Or second? Because the default is in second. And if you’re starting in second, I had the same problem with my 722.3 transmission when I first bought my w126. It refused to upshift out of second gear.

I searched down every problem/solution I could think of. Eventually, mine just took multiple filter and fluid changes. And some trans-x each time.

 

Yep definately 1st gear. I also checked the RPMs on mine with another SL in the neighborhood and I am at least 600 RPMs higher running than his. This is once I get it to upshift by going to N then back to drive. I am basically running one gear too low. I am on my third round of fluid based on draining it for valve body work, modulator replacement, solenoid replacement, etc.... Never heard of Trans-x but just did a search and at this point what do I have to loose. I will give that a try and if it messes something up I can always drain and install new fluid. Thanks for the suggestion.

 

I feel ya. My car, this happened as I was driving it for the very first time, which was after I bought it, on my way to our warehouse (I looked at it and bought it with a dead battery). It took me six weeks to figure out. That down time sucked.

All the best on this!

 

Rats! I was hoping that would help. Now I'm really curious as to what it could be. Unfortunately, auto boxes are not my strong point. Fingers crossed for you!

 

Appreciate any thoughts at this point. It is baffling. I think it is something simple, I just haven't found the simple solution.

 

When I was working on this on my car, the trans-x was recommended as a desperation move. To be followed by a replacement valve body. You may be at that point. Where repair wasn’t enough.

 

I had high revving issues (2000rpm just to get the car moving) and the valve body work cured that. The last time I used an additive it made it worse so that will be a last chance. It only costs me $60 in fluid to replace.

 

@wplaine_95
removed, cleaned, replaced the springs in the valve body- Did you remove the valve body?If you did, did you replace the paper gasket? What springs did replace with? K2 is what you should have replaced, but disturbing those Teflon o-rings is a no-no-no
replaced the kickdown solenoid valve (but not the electrical part). For dumb reasons did you disconnect the kick down switch behind the accelerator pedal? Some cars have this throttle switch on the throttle pedal shaft. Does that switch work.
replaced the vac modulator-Did you vacuum test the new one to see if it holds vacuum? attach a hose to the nipple and suck on it, and see if it holds vacuum.
unplugged the kickdown solenoid with no change
adjusted the modulator all the way with no change
adjusted the Bowden cable both ways with no change (it is pretty loose even fully tightened). Did you feel the springynes of the cable? No springy that means more than likely the pin at the valvebody is disconnected. Disconnect the ball socket from the throttle linkage to feel the springy. The springy feel comes from the valve body.
checked the vac lines to the transmission and all are ok, no leaks. Disconnect the line to the modulator, and add a piece of tubing to the vacuum line from engine. Accelerate the throttle while the car is parked. On the other end of the tubing you feel vacuum, and do you feel it diminish as you accelerate? The diminishing is normal...
fluid is new and at proper level

K1 n K2 orings on the transmission case can be all cooked and brittle hard

Here is a troubleshooting guide

 

Here is a troubleshooting guide
[/Q

Ohhhhhhh. I downloaded that document! Can’t wait for some down time at the office tonight!!

 

Sorry if I missed it earlier, but when did the problem start?
Suddenly?
Possibly after some other work on the car?

 

The transmission started slipping one day and in a week was really bad. No work done on it. I thought the same thing, what did I break.....I just cant find the smoking gun!

 

You may have to gamble it with a 1990-1995 MB(V8 or V12) cars and get a valve body as MB does not make them for sale anymore. Here are 1 2 only two cars in your state, but you may have to drive to SC, Georgia or Virginia.... I used Row 52, but you can use LKQ too

Best of luck,

Martin

 

Thanks Martin...Going to a junk yard to pull one will be a fall project as the car is driveable. I had kind-of ruled out the valve body at this point but I might have missed something. I was just hoping the shift from D to N to D to get upshift would ring a bell with someone who also had a 722.3 tranny. Thanks again, Walter

 

It comes down to the hard seals on the transmission case, but usually the problem B2 piston or seal. These 722.3's-722.5's run super hot compared to 722.6. This is all to the two brake-bands as they are always rubbing where 722.6/722.9 have no brake-bands...

Martin

 

Martin: Thinking back (at 5am lying in bed) I pulled the valve body because the car would barely move from a dead stop in D or R. I would have to rev it to about 2000rpm to get it to start rolling but I am pretty sure it would upshift. After the clean/rebuild of the valve body all that went away (drops into gear and moves instantly) but now have the no upshift. You have given me the kick in the ass to pull the valve body again and double check the parts that really cause shifting. I could have missed something.

 

So that is 2am my time-I'm in REM sleep mode.... by then....

If this would have happen to me, I always attack the B2 piston first the piston seal and plastic sleeve. Removal of valve body is a automatic removal of paper gasket as it is hard/brittle. One cannot go back and place the valve body on the old gasket. Next, do a three to four stage torque on the bolts-ie total torque is 15Nm then do one at 5Nm then 10Nm then 15Nm

I dislike these 722.3-722.5 they are too finicky

Martin

 

So that is 2am my time-I'm in REM sleep mode.... by then....

If this would have happen to me, I always attack the B2 piston first the piston seal and plastic sleeve. Removal of valve body is a automatic removal of paper gasket as it is hard/brittle. One cannot go back and place the valve body on the old gasket. Next, do a three to four stage torque on the bolts-ie total torque is 15Nm then do one at 5Nm then 10Nm then 15Nm

I dislike these 722.3-722.5 they are too finicky

Martin

Thanks, I will follow your advice on the next rainy day and let you know how I fared!

 

THE TRANSMISSION NOW STARTS IN 2ND AND SHIFTS AS IT SHOULD!!!!! It's a festivus miracle! The answers: I pulled the valve body and checked each spring piston combo against the drawings. I found where I incorrectly installed a spring last time. I also found 2 pistons that didn't slide really freely so I cleaned up the raised metal with a jewelers file. I replaced the big gasket this time before valve body reinstall. So bottom line all my issues were valve body related.

Many thanks to all who helped with advice and for giving me the jump start to spend a day (10 hrs) checking the valve body.

 

Hi
there i am in the same boat you were in with my 1999 SL 500 . Any chance we can connect so i can learn a bit more from you ?

Best

 

Glad to hear you got it fixed!!

 

I was having shifting issues with my 772.6 -- flares of 500 rpm or so. I bought a refurbed and upgraded valve body and the seller sent something different than what was described -- and needed. I ended completely disassembling my original unit and putting it all back together with a TransGo kit and new o-rings for the solenoids. Solved all my issues and car shifts great. Chances are you problems are with the valve body -- a careful rebuild and very important to get your fluid level correct on refill and you should be all good to go.

Plenty of helpful members here that have been through it all before. Good luck

 

if everything fails... i got a 95 sl500 rebuilt for you for sale! they only work on 95 sl500