Well, I have some good news and some bad news...

The replacement bolts I have are that inverted torx head. There are six of them. They are all about 1.55" long.

The good news is they are single use so you will need to replace them anyhow... They are aluminum due to the alloy of the transmission case and there is a very specific angle torque procedure.

Did you knock the plastic standpipe off the drain plug before you tried to remove the pan? If not, you couldn't have drained much fluid out. With the standpipe in place and engine running at the right temperature, the drain plug actually sets the correct level. That would account for the mess...

 

I did knock the plastic pipe off, but apparently either not all the way or it settled back on. A bunch more fluid came out when I pushed it up, so I assumed that was it.
I’m letting it drip overnight, and will get a better look tomorrow morning. I suspect the bolts I found hold (or held) on the conductor plate. Definitely single use, as you said.
There was evidence someone had been in the transmission before. The wire looms were not all clipped into place. I suspect a PO or a service shop pulled the conductor plate and put it back in with the old aluminum bolts.
More to come tomorrow morning.

 

That standpipe should pop off and fall to the side.

 

I pulled the valve body and conductor plate this morning. All 4 mounting bolts at the rear end of the valve body were missing (see pic below). This accounts for the 3 bolts found in the pan, with 1 still unaccounted for.
The conductor plate plug was soaked with transmission fluid (see pic below). This seems to be a relatively common issue with these transmissions.
I’ll test the shift solenoids later today.

 

I don’t know about transmissions but there is a good video by mb or another company related to valve body rebuilding and it’s a precise video, I saw it on YouTube . I would guess the 4 bolts missing would not allow the valve body proper pressure to operate the transmission and that wet connector plate would cause issues of communication. Maybe send out the valve body or do a DIY rebuild . And with new bolts properly installed you will likely fix your issues. I would guess it didn’t shift originally from one or two solenoids not working and the person that opened it made all issues worse. Good luck .

 

I guess I misunderstood you. I thought the bolts you found were [supposed to be] holding the pan on. Anyhow, it sounds like you're headed in the right direction. Good luck!

 

had mine all changed over to Stainless Steel, put a touch of anti sieve on them

 

Why did you do that and how did you come up with the new fastener torque value and procedure?

 

I was thinking the same thing with the valve body and pressure. This might explain the complete lack of movement while in-gear. I suspect the fluid was just squirting out the back of the valve body instead of through the network of solenoids, tubes, channels, etc..
The fluid is under anywhere from 80 to 200 psi give or take, so could definitely find its way past seals if the plate is not attached properly.

 

Curious about this as well.

 

Removed silly post

 

Stainless steel bolts will promote corrosion in the alloy metal used in the transmission case. This is the last thing you want! That's why they specified aluminum bolts.

 

Stainless will also not torque the same as the specs for aluminum. There is good reason stainless was not used by the manufacturer.

 

I removed the solenoids from the valve body this morning. All tested either 4.7 or 4.8 Ohms resistance, which is in-spec. Also applied 12v to test action, and all clicked in a happy healthy way.
Half of the solenoids were “blue cap”, others were the standard “black cap”. Here’s what my detective skills are telling me:
- owner experienced bad shifting. At this point car was out of warranty.
- owner took car under the oak tree in his/her backyard (no offense to oak trees or people who work under them…been there done that). Some solenoids were replaced (may have been targeted for specific shifts).
- valve body was put back in using original aluminum mounting bolts, and possibly torqued, possibly just tightened “good and tight”. Owner panicked when a bolt bloke and others didn’t feel right…you know the feeling when bolts almost break. Owner finished assembling, and tested the car. It worked, but he/she knew it was not going to last forever.
-Owner sold car to unsuspecting new owner, who drove it for 10K miles before there were enough heating and cooling cycles for all the bolts at the rear end to fall out. Transmission failed.
-Owner took to European car specialist who deemed the transmission had “failed”, and needed to be replaced.
-Owner did not want to spend that kind of money, towed the car home and parked it.
-Sgt Pepper saw the car on FB marketplace and couldn’t pass up such a cool little SUV.

I’ve probably watched too many detective TV shows. I’m sure it didn’t happen exactly as suggested above, but at a high level, I think it works.
I’m not 100% sure on next steps. Here are the things I’m contemplating…feedback and suggestions would be greatly appreciated:
- send conductor plate for testing and repair. Best case scenario it is fine and I’m out shipping costs. Worst case they find problems and make repairs.
- replace torque converter, since they sometimes fail, and some say it is best practice when overhauling transmission.
- Pull transmission and rebuild, replacing all wear parts including friction plates, o-rings, etc., to ensure a long transmission life. Never done this before, but I’m not intimidated.
- Reassemble as-is with correct bolts and cross my fingers.

I’m not in a big rush to get this on the road, but don’t want to have to fill, drain, unbolt, tear apart, replace, re-bolt, etc. multiple times.

Thoughts and suggestions?

 

My uneducated opinion is the bolts loosening made the trans fail from lack of pressure to properly operate . A torque converter or valve body rebuild will be expensive but I don’t know how much . If you could get it checked by a pro shop for a few hundred I would do it then put it back together. On a different issue , I had my oak tree mechanic tighten my wheel lugs and he used a torque wrench. 2 weeks later or maybe 70 miles later I noticed two lug bolts missing , I then bought a 90$ torque wrench and with the mechanic found his torque wrench was so far out of calibration it was maybe 60-70 lb off. So his torque wrench tightened them to maybe 50lb vs 110. Torque wrenches need to be calibrated periodically ! I have no opinion on the torque converter. I think you will get lucky on your trans and have a good running vehicle 😊 yes get new MB bolts from MB or FCP euro and do the exact mb torque procedure. I heard it’s a bit complicated. A good idea now would be to seal that open trans with plastic to keep out dust. Transmissions need to be clean to operate and not fail .

 

Just noticed that the bolts at the rear end of the valve body sheared off in the transmission housing. This explains why the bolts that were found in the transmission pan were around 1” long, instead of the 1.5” or so of the front bolts. I don’t anticipate too much difficulty extracting them. They should be well-lubricated with transmission fluid, and should not be bottomed out in the housing.

 

I also missed the fact that the bolts were from the valve body. I suspect that Sgt Pepper's scenario is pretty much correct. If it was my GLK (keeping in mind that I'm cheap and lazy) I'd go with the odds and replace just the bolts, and properly install the valve body. It's hard to imagine a valve body being able to work properly in the state he found it in originally, and I suspect that should remedy the issue(s). If SP is a competent wrench-twister, this is a very low-risk option - worst case, he'll have to drop the valve body again to swap solenoids / have it tested, and then he gets to change even more fluid (leaving the condition of the fluid in the transmission even better than it is now).

I wouldn't suggest replacing the torque converter - it's kind of anecdotal, but I can't recall people whinging about failing TCs here (at all...).

 

Sounds stressful getting out broken bolts , good luck 🍀

 

I’m of that mind as well. I’m inherently cheap, and very curious. The bolts are relatively cheap. Pan gasket and filter, along with o-rings for the electrical socket, and fluid. All-in I’ll be less than $250.
Unless someone chimes in with some compelling reasons to make it more complicated, I’ll go down the fast, cheap, and easy road.

 

I would remove the broken bolts and replace them all and give it a try. I have a feeling it will work just fine and you'll have a lovely GLK for a very low price.

 

As suspected, the broken bolts spun out very easily. I was able to grab them with a flat head micro screwdriver, and with very little effort, turned them out. It took all of about 1 minute to get all three out. I’m not a great mathematician but with the broken bolt I was able to get out earlier, and these three, that makes 4 broken bolts. I only found 3 bolt heads. My math shows that I am short 1 bolt head. If I get bored waiting for the shipment from FCP Euro, I’ll slice the filter open to see if it got sucked up in there.
I ordered all necessary parts, including a new pan. Old pan was rusting badly.

 

The shipment came in from FCP Euro today, 1 day early! Transmission fluid, filter, pan, gasket, valve body bolts, pan bolts, and torque converter plug. I also ordered a set of solenoid o-rings from another company, which unfortunately have not arrived yet.
Let the games begin!

 

I spent the afternoon cleaning parts for reassembly. The shift solenoids spent some time in the ultrasonic cleaner, and received new o-rings. New o-rings on the electrical 5-pin (or however many pins) connector. Reassembly was much less messy than tearing apart. My daughter torqued all the bolts, and pumped the fluid in. No absorbent needed 😁. Proceeded as per FCP instructions for torque specs, and filled it back up with Fuchs fluid.
I let the lift down, fired it up, put it into gear, and away I went! Transmission shifted great! No slipping, all gears work great!
Now for all the other fluid changes and new tires. Any recommendations for 19” tires?

 

Sweet! I love it when our SWAGs turn out to be correct! ;-) Congratulations!

 

Continental Extremecontact DWS 06 Plus. Fabulous on the GLK and our Bimmer (and my brothers Audi A8.)