Tris1041

first of all i know there is a lot on this subject but ive been reading up on it for weeks and i haven't really found any good answers for my liking so im posting my own thread i have a 2010 c300 4matic and it has 40k miles so its time for the Trans service. ive been calling tons of dealerships and they are all in the 500-600 range for just the trans service then i tell them i want the torque converter also drained and changed and they want to charge me another 200 just for that.... some dealerships wont even do it. so my question to you guys is what is your opinion on changing the torque converter fluid and also what should i be looking to spend? lastly what is you opinion on a independent shop? i ask because i was quoted like 400 less then the dealer and that included the torque converter drain. thanks

pozi240

Your preliminary findings from the dealership's you contacted are in line with what other members have found (myself included). Some will say they "can't" drain the TC or that they won't do it or that is "not needed". Some will even lie to you and say they will do it, but when you check the invoice, it will say they only used 7-9 litres of fluid (which only accounts for the transmission drain, not the TC as well). The prices they quoted are inline from what I've seen. Now, having said that, my local dealer charges $540 for the transmission service (drain, and filter change) but does not do the TC. A trusted local Mercedes Benz independent shop (he used to work at one of our dealers for years) will do the completed service including TC drain and fill for $350 using OEM fluid and filter.....so, it is possible to do the job for much less and do it completely, you just have to find a shop you trust or do it yourself.

chrisridebike8

Do it at an indy shop. I can't get the dealer to drain the TC. I think it's necessary as there is a lot of fluid in there.

Adi-Benz

GET THE TC DRAINED or potentially suffer a failed 4matic transmission.

pozi240

That is a bit alarmist there Adi. The torque converter is not the weak part of the transmission. The transfer case is different issue all together.

PortC43

Hows anyone know how many quarts of fluid are needed to do the trans and TC ?

pozi240

Both together use approx 9 liters of fluid. Without the TC being drained, the amount varies between 5-7 liters from multiple user's service invoices posted in these forums.

NZ-Merc

When the car is on the hoist and the pan is off the trans and draining to access and remove the converter drain plug is a very simple task and would only take a few minutes.

I don’t know why the service providers make such a big deal out of it, in my mind it 100% has to be done due the large quantity of old oil in there which would contaminate the new oil if it was not drained.

PortC43

That seems too little. Mercedes Parts guy here in the USA said 7 quarts SHOULD DO IT (remember we don't do liters in the US ) But who knows

Adi-Benz

10 qts you need as it is 9.5


and it can cause transfer case to fail yes.

Funkwagen

Draining the torque converter is part of the transmission fluid and filter services as per WIS. It should not be a separate work order item.

I paid about $450 CAD for the service, the full quantity of fluid (was charged for 9L on the work order) used and the TQ drained. Luckily I know the tech who worked on my car

dennish

I would take it to an indy. I did it and its not difficult. Not a dealer specialty service.

pozi240

Yes, but 1 litre = 1.06 US quarts. So 9 litres would be 9.54 quarts (so, you would need 10 quarts overall). If you're only invoiced for 7 quarts, they didn't drain the TC. I think this thread has been beat to death now as Funkwagen and others have also confirmed the same amounts. And Adi is convinced if the torque converter is not drained during transmission service, your transfer case will fail. I suppose anything is possible, but, if you don't drain the TC, you will have 2-3 liters of old fluid mixing in with the 7 liters of fresh fluid. Is this a "bad" thing, not overall since you have a new filter as well, but, the service life of the new fluid will be shortened slightly. Its not a big deal to drain the TC while you're doing the service, so, why not do it.

A important note is, even when draining the TC, you will never get all of the old fluid out of the transmission during drainin unless you flush the cooler and lines, etc. So, having old fluid mix in with the new fluid is not a huge concern but leaving 2 plus liters of fluid in your TC when you don't need to, is a no brainer really.

PortC43

Yes, good points made here ! Thanks for your input. While im in there, might as well drain and fill the Converter as well and do it properly all in one shot

Adi-Benz

Well my transfer case just got fixed so I'm just trying to tell everyone not to skimp on maintanence.

pozi240

You got it fixed Adi? That is great news, share the details. New tranny or rebuild?

OrientBlau

I'd like to hear a little more too. Thanks.

Adi-Benz

My bad guys I was in a rush and I typed that out and ended up giving false hope Mechanic said metal pieces had gone in so there was no fixing it, so gonna replace it with one from another vehicle. I asked the mechanic to let me keep the trans - I'm gonna take it apart myself and rebuild it including the transfer case in my freetime (could be a while). I get car back tuesday so I'll give a sitrep then. Sorry for my misrepresentation guys.