Glyn M Ruck

Guys and gals. This is not intended to cause alarm but to respectfully suggest that you service your 722.9 transmission every 39K miles or 60K Km's as in ROW. We are seeing an increased number of TC et al failures as mileage increases & feel it prudent to inform you while we try to fully understand the failure mode. I should also state that forums such as these concentrate problems as many only post when they have a problem.

https://mbworld.org/forums/c-class-w...need-help.html

Rudeney

+1 on that! Another thing I strongly recommend is to have the dealer flash the TCU with the latest software. After having the (dreaded!) defective timing gear replaced over Christmas, I didn't drive the CLK much until after New Year's. I then experienced some definite slipping and gear slamming on a cold engine when shifting into or our of 2nd gear (1-2, 2-1, 2-3, or 3-2). Once warmed up, it would shift normally. This is typical of low fluid, and I assumed that during the engine job, they might have had to disconnect a line and lost some fluid. I took it back to have it checked, and they promised no transmission lines were opened but they did find the fluid "slightly" low and corrected it. They also flashed new TCU software and proclaimed it good, and yes it is. The new software shifts much smoother. It seems to hold the RPM's up during normal shifts so there's not so harsh of a "grab" into the ear. I suspect that would be better for the transmission in the long run. I have not noticed any degradation in performance or economy, either.

Mine has 35K miles and I asked about going ahead with eh 39K service, but my advisor said to wait. I am not really sure why (after all, it's my money!) but he said that is the way to go. Maybe that's the magic number where the oil begins to break down and is the "sweet spot" for changing? Who knows, but I am definitely going to have it done then!

Glyn M Ruck

Nah! Benz like you to stick to their intervals. Don't be shy to make them listen and ignore their change once BS.

In fact - Johnand - who I consider the board's guru on this transmission is recommending 30K drain intervals to all W203 members with this transmission as they all have the early generation more troublesome versions. John personally owns a 2007, close to final production W203.

TNStangman

Is there a time limit as well that might cause the oil to breakdown. I have a 2005 CLK500 with only 14k miles on it. Do I wait until 39K to service or should I also get it serviced earlier because of time?

Glyn M Ruck

Benz says 4 years or 40K. I left mine in my W203 722.6 for 7 years & it was fine. If I had a 7 speed I would rethink that.

mikata

Glyn, my 320 is from 03/04, it has 50.000km on the clock.
Time for a transmission service?

Glyn M Ruck

Change at 60K & you will be fine. My C240 was 2003 & I changed at 60K Km's as recommended but 7 years. The 722.6 is bullet proof apart from electrohydraulic bush O rings & the odd conductor plate on very early ones. Not 2003. If you change a 722.6 every 60K Km's you will never have mechanical trouble with it.

mikata

Thanks for the info Glyn!

labguy

I realize this is an old thread, but I also know that it is part of other threads as well that stay updated.

So, I have a 2008 CLK350 with just over 38K miles. I went ahead and had mine done and the mechanic reported that the oil appeared "clean" and not too much "gunk" in the pan. I went ahead and updated it with the new pan too.

Thanks to all the contributors on this forum!

_Bondo_

I just got a CLK500 with 56k miles--could not find anywhere in the VMI showing the trans service had been done. Should I be in panic mode to get it done? Tranny bucks a bit between 1st and 2nd when cold and in S mode, but nothing crazy.

06merc500

Mine does the same when cold. Downshifting at a stop is harsh and the shift from 2-3 isn't the most pleasant thing. It's been like that for awhile and is fine when its warmed up. Im assuming its low on fluid then? Im going to make an appointment soon.

Rudeney

There is actually an updated software the dealer can flash on the TCU for you that will help.

labguy

From what I have read, panic is not necessary, just get it done.

MacVidMB-V8

Do you know if this is already part of 2013 DAS system or is it downloaded from Germany for a specific car?

I have done a light search for doing this but haven't found any answers.

I'm 99% certain the Bozos at San Francisco MB didn't do anything they didn't have to do.

Rudeney

You can't do this with a "Chinese clone" version of SDS - only a live, licensed dealer copy of SDS can download the code form MBZ and flash it. I had mine done for about $100 and it made a huge difference. Shifts are much smoother and no "clunk" when slowing to a stop.

mguerrero

New Pan?? please share what you mean as I haven't read about the "new" pan ...

labguy

You can read about it here:
https://mbworld.org/forums/clk-class...ce-thread.html

Glyn M Ruck

Make sure you change both pan & spill tube if necessary.

06merc500

Does anyone know how many arms and legs the transmission flush and tcu flash will cost? So I need to have the pan changed too since im doing the flush?

Rudeney

Regarding the new pan, I am very surprised the MY2008 didn't already have it. I actually thought my 2007 didn't, so I bought one, but then I found it was the revised "sloped" pan.

labguy

That is surprising - I still have the one they took off - it was the old non-sloped one.

_Bondo_

My service manager printed the service schedule for the car, never calls for a trans service--seems odd that it still hasn't been added. My plugs have never been done either, but they seem ok (as ok as plugs can seem from just driving).

Rudeney

The 722.6 was sold as "sealed for life", but later on, MBZ actually issued a "note" (not a TSB, just an email) that told service centers that it would be "acceptable" to do a fluid and filter change at 70K miles. The 722.9 transmission was also sod the same way, but then they began to see some early failures, so they came out with the one-time 39K service. Based on what I saw in mine at 39K, I'll do it EVERY 39K.

Glyn M Ruck

ROW has always been every 39K miles or 60K Km's for both 722.6 & 722.9 ~ even Vietnam!

Only MBUSA fouled up by not listening to Stuttgart & it cost them. Highest transmission claims worldwide.

You must service these transmissions

_Bondo_

What did you see?