cutin

Hello,

I've problem with my CLK 240. When engine is working I've oil leakage form transmission. This is a one drop per second. Leakage stops when engine is turned off. I found the place where oil is going from and this is a small whole in black rectangle cap on the bottom of transmission housing near to connection with engine. I marked on yellow that place.





I wondering is that oil leakgage from a seal on clutch shaft.




Is that repair realy difficult to do myself in garage?

Yidney

Have you determined what fluid is actually leaking - transmission fluid or engine oil? The rear main seal on the engine may be leaking.

Yidney

At one drop per second, it will not take long for a noticeable drop in fluid level. Have you checked your engine oil level? If it's transmission fluid leaking that fast, it won't be too long until your transmission stops working correctly because of a low fluid level.

Rudeney

As Yidney said, it could be engine oil, which wold be coming from the rear main seal, or it could be transmission fluid, which would most likely come from the pump seal that you pictured. Transmission oil should be more red/burgundy in color, while engine oil will be golden/black.

In either case, you'll have to pull the transmission to fix it. Best case is that it's the rear main seal. With the transmission out, you remove the flywheel (technically called a flex plat) and the seal bolts on right behind it. If it's the transmission fluid pump seal, you have to disassemble the transmission to get to it (i.e. replace the pump, which is bolted on from the inside). I replaced the pump on my 722.9 in the CLK550 and it was a pretty major job, but certainly possible with the right tools and skills.

So first, let's find out what is leaking based on the fluid. As Yidney suggests, check the fluid levels, which means investing in dipsticks for both the engine and transmission.

cutin

Thanks for advice guys. I will check the color of fluid tommorow. So, it doesn't matter what seal is damaged the work should be going the same way. Put transmission off and replace the seal which side... engine or transsmision will see

Rudeney

Yes, both require dropping the transmission. This means draining it, removing its wiring, linkage, and cooling lines, then removing the exhaust system, detaching the torque converter from the flywheel, then unbolting the bell housing, driveshaft and rear support bracket. The transmission can then be removed.

Now, if it's the rear seal on the engine, all you have to do is unbolt the flywheel, and the seal is behind it, held in place by a cover with a few bolts. This can likely all be done in your garage wit the car on jack stands, and a cheap transmission floor jack.

If it's the transmission seal on the pump, things get more complicated. You will have to remove the transmission and take it to a workbench. It's unlikely you'll be able to lift the car high enough in your garage on jack stands to get the transmission out on a floor jack. I did this on my CLK, bu I had to use larger jack stands than the normal ones you find at auto parts stores. Evan at that, I could not lift it high enough to roll the transmission out with it on the jack - I had to take it off the jack, then slide it out. It is VERY heavy to be handling under a car lifted 22 inches off the ground, but it can be done.

Now, once you have the transmission out, you have more challenges. First, you have to disassemble the entire unit to get to the pump. It bolts on from the inside. You have to remove the main bolt at the tail of the unit. I had to use a 600 lb-ft pneumatic impact wrench to get it to budge. Then, you have the challenge of pulling things apart without gear, bearings and clutches coming off. Actually, they will, so you need to study how they work to get them all back in place.

So, my advice - pray it's the rear main seal on the engine! :-)

Yidney

And if you have never seen dirty tranny fluid before, don't conclude "it's brown - it must be engine oil." It will also be brown, but a different brown. More pinkish and less blackish.

Rudeney

Transmission fluid stinks, too. It smells "fishy" instead of "oily".

cutin

Thanks Rudeney, for your information about process. It's very important for me.

Today car was placed on a lift and I have more photos.






On thursday I will remove the transmission.

Yidney

Looks like engine oil to me.

Yidney

As much as I like to DIY, and would not be afraid to drop a tranny, doing that job laying on my back with limited room to work just doesn't pass my life is too short test. Maybe if it had to be rebuilt or something and the money savings were huge, but not for a rear main seal. That job can be done by any competent mechanic and is not that grossly expensive.

nauticalx

no disrespect -- but if you can't readily tell if it's transmission fluid or engine oil, this is not a DIY job for you. take it to a pro.

floridawriter

That's an oil leak.

mbnz230

Looks like I have this same leak on my 2004 clk500. It's a very common problem it seems. this pic was taken a week or two ago.

Rudeney

Yep, looks like engine oil to me, too. Most likely the rear seal. I will second the comment that this may not be a DIY. Dropping the transmission is not an easy task if you don't have the right tools and skills.

cutin

No worries lads I will do it with my friend/mechanic. We have essential tools, skills (we are polish ). And the moment CLK is on the lift so dropping the transission off isn't the proplem for us. In next 2-3 day we are starting

Right it wil be be my first time but Rudeney gave me recipe how to do it step by step. Stay cool



I have a question about one plug I found is dissconnected. Is located on the left bottom side of bumper near the wheel.

Rudeney

If I were you, I'd get a copy of WIS. You should be able to find it online for around US$30. There are also other places where you may find it (try ******* forums). You will need this for the step-by-step procedures and torque values.

Besides the usual cautions about safety, one big warning is that when you re-mate the engine and transmission, make 100% certain the the torque converter is properly seated in the transmission pump. Also make sure the torque converter properly mates to the flywheel. If all of this is correct, then everything will fit together like a glove. If there is any space among any parts (i.e. torque converter to flywheel or between the transmission/engine bell housings then STOP - something is not right! Do NOT "pull it in" wiht the bolts!

cutin

I thougt about marking every parts working together during dropping transmision.

For example:
- flywheel to engine housing,
- flywheel to torque converter
- torque converter to transmission housing
- torque converter to pressure pump

I will try to find more info about operation and torque values on ******* forum. If someone have that information Please paste it in that thread. Thanks

DanielFD

That does not look like an MB connector to me. I think it could be for an HID kit.

xsever

I had a similar leakage on my 05 CLK 320 with the 722.6 and below are the parts my mechanic friend replaced:

Transmission Pump Seal 018-997-04-47
Oil Filter Housing Seal Ring - Housing to Timing Case 1121840061
Crankshaft Seal 112-997-02-46

DanielFD

did the same at the same "mechanic friend"

cutin

I'm wondering how to unscrew torque converter from flywheel? Is there any small place to put in a wrench ? Should I do it like that ?

Dissconect rear drive axcle from transmission then unscrew torque converter from flywheel and help myself by rotating rear drive set the bolts in proper place.

I found the video how to do it:

Rudeney

The torque converter attaches to the flywheel with 6 bolts. On the 722.6 transmission, the bolts go through the front of the flywheel and tap into threads in the torque converter. There is an access port on the front of the engine bell housing where you insert a socket wrench. You have to rotate the engine via a wrench on the harmonic balancer bolt to get to all of them.

cutin

I have already droped the transmission out !!! You are right! I was an oil leakage But I want to replace both... rear main and transmission seal. I have to change the transmission fluid because when I drained it the color wasn't clear, filter and seal on pan. We will assemble tomorrow.

I need some torques for:

- flywheel to crankshaft
- flywheel to torque converter
- transmission housing to engine
- rear axcle to rubber joint
- bolts on transmission pan
- transmission pan drain bolt

I took many photos maybe they will be usefull for someone in future

Rudeney

- flywheel to crankshaft: 45Nm + 90-degrees
- flywheel to torque converter: 42Nm
- transmission housing to engine: 39Nm
- rear axcle to rubber joint: M10 bolts = 40Nm, M12 bolts = 60Nm
- bolts on transmission pan: 8Nm
- transmission pan drain bolt: 20Nm