Tranny Service Nightmare!
 

Hey Gents,

Let me begin by saying my car was mint and drove perfectly before I did the spring maintenance. I did have a slight drip on my driveway, which I think was the transmission fluid.

I've been having some serious issues with my tranny after doing a tranny service 3 weeks ago. I got it changed at my local shop and everything seemed well, a diff mechanic did work on it(ill get back to this later). I drove home normally nothing to aggressive. The mechanic noticed my pan was covered in fluid and determined it was my gaskets that were leaking, I don't see a leak currently. He said he took out about 3.7L and added back around the same.

This is what I used:
https://www.fcpeuro.com/products/mer...-kit-722-6fck1

I came home and parked the car for 3 weeks and went on a vacation. Upon returning first thing is PINK SHRIMP moved into my Instrument Cluster.

Here is where it begins:
I went for a drive the same night and was going 80 MPH around twisties when I hit WOT, the car suddenly jerked a bit when it downshifted and shot easily to 110 as I let off the gas the car jerked about 1 second later and slipped into NEUTRAL.

I panicked and though the transmission was blown, all I had to do was restart the car and it drove fine again. I spent 2-3 hours driving the following week and trying to recreate the situation to no avail..that is until tonight.

I was driving the same road and same pattern and this time as I let off when it downshifted it slipped into neutral very hard and i got a CHECK ENGINE LIGHT. I got home and connected the STAR I got P2069 and P2500.

https://cimg4.ibsrv.net/gimg/www.mbw...60dc8359e.jpeg


The car drives fine and slow and under part throttle, but under WOT is where this occurs and high speeds...Also IDK if it's in my head but after letting off after a hard pull..if it didnt shift into neutral..i notice the car keeping high rpms for 10 seconds before downshifting(4K+)(higher gear)

At this point I searched the forums, I'm down to 2 theories.

• Low on Fluid- Perhaps, I should've stuck to OEM but I hear they are reverse compatible and can be interchanged. Also I don't think he warmed the car long enough before adding more, but he did use the tube method w/pump and he said it was flowing back down which indicates full...or so I think..Old fluid was good too and no shavings.
• Fluid wicked up into the TCU

I'm not sure what else it could be at this point and just doing the process of elimination. i wish I never touched anything or did any maintenance and none of this would've occurred. That bothers me the most , I tried to do a good thing and got screwed :/

Any thoughts or ideas? Did anyone have anything similar? Should I do a full flush now or where do I even go from here.

Thanks

Did the mechanic use the correct fluid?

Yea, this is what was used Pentonsin 134, I read it was MB approved before using it.

https://www.fcpeuro.com/products/mer...-kit-722-6fck1

It's the correct fluid. Pentonsin ATF 134. They normally take 4 ltrs. Sometimes a tad more depending how long it was draining for. Did you replace multi plug whilst there as these are common faults

Nope, I didn't check or even look at the Pilot Adapter bushing.

Have you checked the fluid level yourself yet? I presume the regular 722.6 dipstick fits all vehicles with the 5 speed.

I don’t have a dipstick for the tranny laying around. I did some more digging overfilling could be just as bad!

Its imperative fluid level is checked ASAP.

Im about to stick my phone under the car and try to see if I can see if anything is wet or the pilot bushing was the source of the leak previously.

Its Sunday tomm, I’m considering driving to my shop as this is just glued in my mind.

Yeah it sure sounds like fluid levels being low. Same happened to me after a service, these are very touchy on having the correct level! Just make sure you're reading the right dipstick tube, I've heard of that happening too :zoom:

I always change the multi plug with gearbox service as they are prone to leaking. I would check both tranny oil level and multi plug. Oil level is best checked at 80 degrees and to check multi plug remove electrical connector to see if wet with oil

Jeez, I hope so. Yea I should've changed that connector when I did the service, I wasn't even thinking about it in the moment.

Hopefully this will be resolved with a good ending.

Perhaps I should order it now and go to the shop with it this time..I was planning on going tomm but I'm home with a bad COLD

I got a dipstick from ebay originally but I think all the good online parts stores sell them now. You may struggle to get 80 degree readings. Even after really hard driving I struggled to get much over 60-70C in summer. There is a chart floating around which allows you to correlate the temperature and level reading at the hot end. I guess this is why many of us DIY. I replaced the pilot bush as soon as I got my car. Transmission fluid came out when the plug was removed.
It is really the job of a good mechanic to make these suggestions and question the previous service history to work out if anything else needs doing and good business practice as they can potentially make more money.

Yea, I wonder how I’m going to get it to 80C. I’ll let the shop figure it out. I read somewhere here a dude hit the brake and let it rev up to 2k RPMS which got the TQ converter hot. It’s over an hour drive to the shop since I keep my car out of the city. Hopefully that will do.

I agree, the main mechanic was out this guy was a noob. He didn’t know the SL has 2 drain plugs for the engine oil and nearly forgot the magnet for the transmission pan. This is why I’m thinking he over or under poured. ****, I’m getting angry just thinking about it. I thought the pump method was idiot proof thru the transmission pan as it just goes back thru the overflow ****. I guess not. But we’ll see the real reason soon enough

I have done the rev brake method also but it still takes a while to get there. I would drive around to get it hot then try that method to get close but I wouldn't insist on 80C. Post 6 has the chart.
https://mbworld.org/forums/w211-amg/...id-dealer.html
I think you need a new mechanic once this is finished. I am not aware of any overflow on the 722.6 transmissions. If the pan is dropped to change the filter it is best to always check the level as you won't get the exact volume from what you took out through the drain plug as it is recessed into the pan. If you simply suck the fluid out through the fill tube, then you can put the exact same amount back in and be pretty happy with it. I used a 20mL syringe to get the exact right level, that was overboard.

So meticulous!

This is what he did he drained it thru the drain plug and said 3.7 came out..then he changed the filter and pumped some back in..then he started the car and said he was checking the level and added some more back in. At the end he said this is all it would take as it was coming back down thru the tube. He filled it thru the pan method with the pressurized tube pump whatever the f it’s called. Fcp Euro has a video of this 722.9 style.

I know many people, even trained techs, will just measure the quantity of fluid drained, and use that for the replacement quantity. I prefer to actually measure the level and set it based on what it should be according to the oil temperature and the dipstick measurement (722.6) or flow rate from the drain (722.9). Refilling the 722.9 is not rocket science. There are a few challenges. First, you need to be able to safely lift the car with sufficient clearance to access the drain with the pan being level. Second, you need a way to pump fluid in through the drain plug. I use an Assenmacher pump, but others have simply bought the threaded tube that screws into the drain plug opening and then used a cheap hand operated "fluid transfer pump" to fill. Using an IR thermometer on the center of the pan gives the same reading as SDS in terms of temperature. The other challenge is that the drip rate has to be checked at 45C/113F, which is not cold and not full operating temp, so sometimes it can be difficult to get it to just that temp without going over.

Thanks Rudney, yep I’m on the 722.6 platform. I can’t wait to take it to the shop and have them measure the damn fluid level. Next Sunday it is. Stay tuned hopefully this will help people in the future who run into this.

Good luck to you on this mission Sir.

I don't know how the mechanic could apply the 722.9 method to the 722.6.

He couldn't. The drip rate level check on the 722.9 is created by the plastic "overflow tube" that sits on top of the opening for the drain plug. The 722.6 has no such tube. it is checked strictly by a shop use dipstick.

He did! Now I’m scared.

i thought it made no diff since it all goes to the same place(the pan)..but here we are. I’m guessing him adding the same amount back didn’t work since I’m in this situation..

just purchased

Yep completely different servicing procedure. The 722.9 doesn't even have a dipstick tube from memory and the 722.6 has a different pan.

Yep, thats correct.

Pretty much, my fluid level was never checked.

Dipstick is arrving tommorrow and I won't even be here :/

I'm guessing 25C for the cold read, would be me just letting the car warm up to operating temp in park and then checking it. I don't have the IR gun, perhaps star has a parameter where I can see the temp?

Yes you are supposed to use star to read the fluid temperature. I use an IR gun too as I don't have star. 25 degrees is usually just after starting the car unless you live somewhere very cold.

Sweet, the cold read should give me a good preliminary..in the meanwhile i'll research in STAR where I find the temp reading.