Hey guys, I'm stuck what to do next. My transmission is slipping primarily from stop. As the engine warms up it rarely occurs.

I've gone to 3 mechanics and received 3 different diagnosis.

1. First mechanic wants to rebuild the transmission
2. A transmission specialist, suspects the oil leak I have is actually from transmission lines. A previous mechanic said not to worry yet, it's minimal leak from the turbos. If the leak is not the problem and the oil is replaced it will likely require a transmission rebuild immediately as the slipping will likely get worse with the new oil.
3. 3rd mechanic recommended a software update first. He said there is too much oil under the engine for him to determine if it is from the lines.

My challenge is getting a different diagnosis from 3 different mechanics.

I suspect the oil leak is transmission oil because the oil level had not changed at after months of that small leak.

All of the mechanics are recommending I get rid of it because they are known for way too many issues.

I don't know what to do next. What do you folks recommend?

 

How many miles on the car and when was the last time tranny oil was changed?

 

140KM/86M, I don't see any indication of it being changed in the service booklet. I purchased it with 90K, 1.5 yrs ago.
The transmission specialist said he cautions changing at this point because the thick viscosity is probably preventing it from totally failing.

 

Try to call MB dealer and see if they can locate any services records by VIN number,
I just check maintenance schedule for my 2014 ML BT OM642, and first tranny oil and filter change recommended at 70K miles about 113K Km. not too far from where you are now,
still not clear if there is a leak or not and how bad. Can you confirm the correct ATF level at least?

 

Apparently, because the system is closed and there is no dip stick there is no way to check levels.

 

kind of closed system.
watching this video and at around 2.40 mins mark the most important part, knowledgeable tech must know this.

 

If I was in your position I would have the trans serviced and fit a new filter.

Whilst the pan was off the Mechanic would/should/could check for any stray bits or wear material in the pan.

If none chuck in a filter and new oil and see what happens.

I wouldn't rebuild one of these trans I would fit a take-off from a wreck.

It would only take a few hours to swap over and a visit to a Dealer to get it to talk to the car and you should be good.

Could be worth tracing the oil leak. First clean under the car and drive it for a few days. Any new oil should lead you to the leak.

 

Have the transmission serviced at an MB dealer. Ignore any warnings they give you about thicker fluid, etc. There isn't much to lose at this point. The transmission is slipping, action needs taken.

 

Thanks for the reply DanD. You forgot to add the link the to video. Please post it.

 

Thanks for the feedback Zuffen. Makes sense.

 

Thanks for the reply chassis.. I'm going to have the oil changed and see what happens.

 

This is funny )) here is the link?

 

Agree 100%. Have the fluid and filter changed at a MB dealer as it is overdue, AND have them update the ECM and TCM with the latest software. My 2014 ML350 BT had pretty bad cold slip and since it was a CPO the dealer updated TCM and ECM software and it was a night and day difference. Slip is gone and the transmission shifts perfectly. Good luck.

 

Let’s start with a trans fluid flush and filter change. Then do a TCU reset. Get back to us and let us know what happens. I find it hard to believe a trans needs a rebuilt from only 2012. Unless it has like 300k miles and never had a fluid change

 

Thanks Johnand, I'm feeling hopeful.

 

Thanks for the reply. I was shocked as well considering it's a MB. Based on all the posts I am seeing in this forum, anything is possible. The crazy thing is I replaced my last car because the transmission failed just over 200 KM. It was a Nissan Altima, it died about 10/20,000 KM over the extended warranty for their CVT transmission.

I'll provide an update.

 

Check with McNally auto in Toronto (Keel & Finch) ...Charlie is specialized in MB cars and many times he fixed problem for me. When I change transmission fluid, I am dealing only with him.

Not sure about your location but it could be my first stop ...

 

You might consider adding a fluorescent leak detecting dye to the engine oil to trace your leak.

 

Update, yesterday MB dealer completed the software update. No change. They also said that the oil leaking is from the oil cooler not the transmission (a common problem). They recommended doing the service. That’s $325 for the software update and just over $500 for the service. I decided I would use a small shop for the service since this investigation is really starting to add up and I wasn’t sure where it would stop.

A mechanic recommended I check with a Mr. Mechanic in Pickering, Ontario.

After explaining the situation, he asks if the dealer checked the oil level? Nope, they didn’t. I didn’t think they could because it’s a closed system. Mr Mechanic says, well all they have to do open it and if oil comes out there is oil and if not that’s likely the problem. That should be the first thing you check.

He opens the transmission, no oil is leaking. He added over 2 liters. It stopped slipping right away and the changes were smoother. He suggested I drive it for a few days and see what happens. If it doesn’t slip then do a service.

He also uncovered that oil leaking is from both the engine and the transmission lines. The oil has different colours. I guess this is what comes with 40 years of experience. He not only solved the mystery, his costs to repair is far more affordable than 4 mechanics that looked at it.

I feel like I just dodged a bullet. If I followed the first guy I would have paid $3,500 for a rebuild.

Anyways, thanks again to everyone that provided feedback.

I told Ken the owner of the shop that I would give him a plug on here. He was great to deal with, easy to talk to and explained everything really well. His website is https://www.mistertransmission.com/pickering

For your reference the errors were:

0894 the gear is implausible or the transmission is slipping
0732 the gear is implausible or the transmission is slipping (Gear (0))
0731 Gear 1 is implausible or the transmission is slipping (Gear (1)

 

First of all there IS a way to check the transmission fluid level as specified in WIS. You need to start the engine and let it idle, and use STAR/Xentry to monitor the transmission fluid temperature. Some people use a infrared temp probe and look at the temp of the transmission pan. This method works fine as well. When it reaches a specific temperature(I don't remember the exact number but not difficult to find), remove the screw on the bottom of the tranny pan and see if fluid comes out. If no fluid comes out, it's too low and you need to add. The screw hole is also the add port. With normal fluid level the tranny fluid should be dripping out. If it pours out, then you have too much in the tranny. Wait for the pouring to finish and when it turns to dripping, it's good.

It looks like your problem was simply a fluid leak.