macsp

Thanks. I am trying to understand the overall location of the TC drain screw once the car is lifted. It looks like a single screw that uses allen key.

dave2001auto

Yes, there is only one on the TC. It's wheel-like, so needs to be rotated until the drain plug is at 6 o'clock position. Lots of people use a large screw driver or pry bar to rotate the TC clockwise (front to rear view).

MBZ sell the TC plug with seal for about $4. The plug comes pre-treated with a lock tight material. There are two common sizes that MBZ uses. The part department can give the right size with the VIN.

Uncle

I serviced the transmission on my 2010 C300 2wd this weekend. Thanks to the forum it went very well. A few things that I can add:
1) The crankshaft nut is 27mm, and it allows you to easily rotate the engine to get to the TC drain plug. Engine turns clockwise as you face it.
2) There is a catalytic converter bracket beneath the transmission that does block access to the drain plug. It is easily removed with six bolts, and once off, the fluid will drain from the TC without dribbling.
3) I made a fill adapter using a 12x1.5 drain plug from O'reilly's. Drilled a hole thru it, and used JB Weld to attach a barbed nipple. Cost about $6.00.
4) Used a drill powered Jabsco pump to fill the transmission. I use this pump on my sailboats to drain the engine oil.
5) Judged the temperature by feel. It worked well, and the spill over worked fine.
All the other stuff is in the other emails, so I won't bother with those details.

macsp

Alright....took the car to the same dealer and they lifted up. Before taking me in, they realized there is TC drain screw!!! I went in and confirmed it. Now the dealer is offering to do the entire drain for FREE. They charged me less amount for the transmission drain because it didn't include the TC. Normally the complete drain is about $500 here. The fact is that they are correcting their mistake, but I need more from them to make me happy

Had I not read this thread/discussion forum, I would be just screwed up as many!

Thanks folks...great and helpful forum for people like me with no background in the vehicle repair/components.

Carsy

Just shows that persistence pays. Congrats.

Says little for the expertise of the dealership.

tmsiegle

That's great news! Must be a relief
Now I just need to wait and see if the folks here in Calgary give me the same runaround.

macsp

Yep, I sent a strong email to the Service department saying they lost my trust!!!

macsp

Indeed it is a big relief...just got a call back the dealer saying the car is ready for pickup and they used 9.5L of fluid this time.

They also confirm that the transmission fluid has to be changed only ONCE in the lifetime of the car. I assume this is true...or do I have to do more reading on that claim as well?

tmsiegle

Seems to me that this is supposed to be done every 60,000 km...at least you have lots of time now to figure that out

Carsy

That's how I read it too.

Pete7874

Depends on how you define 'lifetime'.

dennisfaul

Hi Guys,

I'm pretty sure I have one of the 722.9 gearboxes without the TC drain plug. I recently serviced the my box but could not find the drain plug. My question is how to I now go about replacing all the fluid including the TC fluid if I don't have a TC drain plug.

Any help on this problem will be greatly appreciated.

dave2001auto

c320 cdi ? Are you in the UK? I couldn't find a small diesel but would like one in the US.

Check to see if mbz sell the TC plug for your car using the VIN. See Wiki for a copy of the "flushing or pumping" out the atf

https://mbworld.org/wiki/images/f/f1...nflush2-1-.pdf
The 722.9 will use a similar method, except no dipstick tube and the use of a weir tube to adjust the atf level. See AP27.00-P-2702W for the filling procedure.

2009 e320 bluetec

mmike

are we sure that the TC has a plug on all W204 722.9 transmission? i talked to an indy and the dealer and both assure me that my vehicle w204 does not have a tc plug

Glyn M Ruck

A 2010 should have a drain plug. From approx August 2010 build onward they are 722.9 Plus transmissions with 120,000Km drain & the new Blue 236.15 fluid.

Most dealers appear too lazy to remove the plastic plug in the bellhousing, rotate the engine until the TC plug lines up with the hole & remove it.

It should never be necessary to do the 722.6 flush procedure on a 722.9. That is for post 1999 722.6 transmissions that had their TC drain plug removed by some cost saving bean counter.

With 722.9 only a very few early transmission had no drain plug mainly fitted to S Class. Even late 7 speed W203's had a drain plug.

Uncle

My 2010 C300, 2wd, has a TC drain plug. I did the service three weeks ago.

Glyn M Ruck

There you go. As it should be!

Carsy

Hello Glyn,

Interested to know the latest thinking on whether to flush my 5 speed .(no drain plug).

The dealers mechanic who I trust said to just drain it & I think in the past you have said the same as long as the fluid is clean & not burnt.

At the 50,000 km drain the fluid was clean .

All this 'religious fervour' of complete draining of the 7 speed , is making me twitchy !!.

Thank you.

Young John.

Glyn M Ruck

JC ~ The 7 speed stresses it's fluid charge considerably more than the 5 speed. All those extra gear changes, clutch slips & lock ups. The fluid never looks great out of a 7 speed.

Carsy

Thank you Glyn.

Makes me wonder about the oppositions 8 speed!

The old ZF 4 speed always just needed a regular drain too & went on uncomplaining for ever.

Glyn M Ruck

Benz is developing a 9 speed as we speak.

mmike

Glyn-- Is there any documentation that I can bring in to prove to them that there is a TC drain plug?

Carsy

There has to be a balance between a gearbox for ever changing & smoothness, economy etc.?

Why not develop the DAF cones & belt system ?

spyked

In the U.S., the 722.9 Plus only started for 2012 model year. C250 and C350 only. C300 got it in 2013.

Still looking for fluid CAPACITY (different for RWD and 4MATIC) and drain instructions on "Plus" transmissions and TCs with the new thin fluid and long drain intervals.

Glyn M Ruck

There is WIS documentation on the Johnand DIY service thread & the "I serviced my transmission but ---" thread & in the Wiki

A number of manufacturers have developed CVT's but there are efficiency & other issues & customers don't like the driving experience.

Thanks for the US intro dates. The plants must have been working off stock of the previous transmission.