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I recently performed the AT fluid and filter change on our 2016 C300 with 33k miles - checked here for a thread but didn't see any so wanted to share a few thought on how the experience differed from doing the job on our 2008 GL. While this thread is for the GL it is helpful: Transmission Pan Bolt Torque Specs

  • Beginning with the obvious, Mercedes updated the fluid around 2010 so it is now blue/green rather than red.
  • The pan came off more easily though make sure you cut the two zip ties holding the wire to the pan prior to loosening the bolts. I tilted the pan down at the front of the vehicle first and managed to get all the remaining fluid into my catch pan with no spills.
  • Draining the Torque Converter (TC) is more difficult because the access port is on the side of the housing rather than the bottom. Accessing it is easy from a clearance perspective, but the fluid drains into the housing rather than coming out the access port and then dripped out slowly. I didn't want to deal with the cleanup so stuck the rigid hose that came with my Mighty Vac fluid dispensing system (outer diameter ~9/32 or ~7.25mm) into the drain hole so that I could direct the fluid into my pan and that worked well with no leakage. its possible there is a tool made for this purpose that would thread into the TC drain but the hose worked well for me. Then to clean-up the bit that did drip into the housing I sprayed simple green in the port (once the bolt was reinstalled) followed by water which ran clear fairly quickly.
  • Refill capacity was significantly more than expected. Mercedes says 6 liters if you drain the pan and TC but I refilled a total of 8.2 liters (9 minus 0.8 flow back). I suspect the coolant lines drained too which is a good thing in my opinion. Just buy 9 liters if you plan to drain the TC.
  • Avoid the aftermarket stretch torque pan bolts that come in kits from Pelican - I snapped one on each job getting to the 4nm +180 degrees so I don't think it was something I did. The replacement Mercedes bolts worked perfectly. Next time I'll do the job with Mercedes gaskets and bolts the first time.
  • The old fluid still looked pretty good - it was still blue though the single magnet and bottom of pan had lots of sludge on them. I put two more magnets that came with the Pelican kit into the pan
Thanks.
 

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I recently performed the AT fluid and filter change on our 2016 C300 with 33k miles - checked here for a thread but didn't see any so wanted to share a few thought on how the experience differed from doing the job on our 2008 GL. While this thread is for the GL it is helpful: Transmission Pan Bolt Torque Specs

  • Beginning with the obvious, Mercedes updated the fluid around 2010 so it is now blue/green rather than red.
  • The pan came off more easily though make sure you cut the two zip ties holding the wire to the pan prior to loosening the bolts. I tilted the pan down at the front of the vehicle first and managed to get all the remaining fluid into my catch pan with no spills.
  • Draining the Torque Converter (TC) is more difficult because the access port is on the side of the housing rather than the bottom. Accessing it is easy from a clearance perspective, but the fluid drains into the housing rather than coming out the access port and then dripped out slowly. I didn't want to deal with the cleanup so stuck the rigid hose that came with my Mighty Vac fluid dispensing system (outer diameter ~9/32 or ~7.25mm) into the drain hole so that I could direct the fluid into my pan and that worked well with no leakage. its possible there is a tool made for this purpose that would thread into the TC drain but the hose worked well for me. Then to clean-up the bit that did drip into the housing I sprayed simple green in the port (once the bolt was reinstalled) followed by water which ran clear fairly quickly.
  • Refill capacity was significantly more than expected. Mercedes says 6 liters if you drain the pan and TC but I refilled a total of 8.2 liters (9 minus 0.8 flow back). I suspect the coolant lines drained too which is a good thing in my opinion. Just buy 9 liters if you plan to drain the TC.
  • Avoid the aftermarket stretch torque pan bolts that come in kits from Pelican - I snapped one on each job getting to the 4nm +180 degrees so I don't think it was something I did. The replacement Mercedes bolts worked perfectly. Next time I'll do the job with Mercedes gaskets and bolts the first time.
  • The old fluid still looked pretty good - it was still blue though the single magnet and bottom of pan had lots of sludge on them. I put two more magnets that came with the Pelican kit into the pan
Thanks.
Did you heat the trans to 45 degrees to get the fluid level correct.


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2006 ML320 CDi, 3.0-litre Diesel 7G-Tronic
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Yes you can overfill if you level when it's cold, this might explain the extra 2 litres you put in.

Why did you decide to change at 33k miles?

I ask because ZF and others recommend 70k miles, 100k km, after they abandoned their daft "Sealed for Life" stance.

My S Type Jag with the ZF 6HP26 took around 9.5 litres, the TC takes around 3 litres so most kits come with only 7 litres of fluid since the TC has no drain unlike my E320. To flush it all there are mechies with full exchange machines such as the Launch 501 which flush out all the old fluid by running the engine. Those needed around 14 litres in all to flush out the 10 litres in the box and TC.

PS: Well done by the way, it's not a job many would take on!

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Discussion Starter #5
Yes you can overfill if you level when it's cold, this might explain the extra 2 litres you put in.

Why did you decide to change at 33k miles?

I ask because ZF and others recommend 70k miles, 100k km, after they abandoned their daft "Sealed for Life" stance.

My S Type Jag with the ZF 6HP26 took around 9.5 litres, the TC takes around 3 litres so most kits come with only 7 litres of fluid since the TC has no drain unlike my E320. To flush it all there are mechies with full exchange machines such as the Launch 501 which flush out all the old fluid by running the engine. Those needed around 14 litres in all to flush out the 10 litres in the box and TC.

PS: Well done by the way, it's not a job many would take on!

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Yes, filled it at temp. Maintenance schedule recommended once at 30k then sealed for life, so this was actually 3k overdue. Incidentally, I followed the "sealed for life" directive with our GL but it developed a shudder from 2nd to 3rd at 130k. Changing the fluid (which was black) corrected the issue. Will make it a point to change more frequently going forward - thinking every 40k.
 

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Discussion Starter #6
Yes, filled it at temp. Maintenance schedule recommended once at 30k then sealed for life, so this was actually 3k overdue. Incidentally, I followed the "sealed for life" directive with our GL but it developed a shudder from 2nd to 3rd at 130k. Changing the fluid (which was black) corrected the issue. Will make it a point to change more frequently going forward - thinking every 40k.
 

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2006 ML320 CDi, 3.0-litre Diesel 7G-Tronic
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Good stuff bud.

Does your car have the 7G-Tronic gearbox, or which?

I'm surprised by the 30K though.

Is the filter a metal one?

If you have a mechie with a full fluid exchange machine near you, you can change just the fluid every other time, like next 40k then every 80k after that to save a bit of time and money, and change the filter at next 80k then 80k after that, leapfrogging, if you own the car long enough.

Anyway, good work! :)

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2006 ML320 CDi, 3.0-litre Diesel 7G-Tronic
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Jaguar refused to open any gearbox and would only replace the gearbox for around £3,500 plus £1,500 labour charges during the "Sealed for Life" campaign, and ZF also declined other than full refurb which would also cost around £5,000.

Even when ZF rolled over, Jaguar said they had received no instructions or verification of that. They upset an awful lot of long-standing new jaguar buyers.

My local dealer service manager told me to take it to an auto-transmission specialist, but when I found there were original ZF sump kits on eBay from Germany, I found a BMW independent who was familiar with the ZF box on BMWs, and had the fluid exchange machine, and that's what we did.

They were a bit uncertain to begin, it was their first time doing the filter change as a service, instead of replacing used boxes, or just replacing the fluid, they had only recently removed and sent off for repair a Mechatronix unit and reinstalled it, and also their first Jaguar. I gave them lots of moral support, plied with coffees as you can imagine, and they found it was a piece of cake. There are a couple of seals and some plastic tubes on the ZF box that should be replaced as a preventive maintenance, which mean dropping the Mechatronix unit, but that was easy too, only 11 additional bolts to undo.

Look into seals for next time you open your box.

All good stuff, the last auto gearbox I took out and fiddled with myself was about 1977, on a Ford Capri, and a Sunbeam Rapier before that, and a Ford Zephyr 6 manual plus replacing a couple of other clutches on even older cars!

Oh, arr, Jim laaad! Them were tha days - when my knees didn't bite me! :)
 

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Discussion Starter #9
Jim-ML320W164 its the transmission Mercedes refers to as 722.9 - seems to be what they use in most of their cars. To be clear I didn't open the transmission - I only dropped the pan. I suspect the dealer does this too - simply flushing the fluid (as they do with coolant) wouldn't clean any of the gunk that collects in the pan and on the magnet(s)). The only plastic tube I'm familiar with is the filler tube that sets the correct fluid level in the pan at the time of filling.
 

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2006 ML320 CDi, 3.0-litre Diesel 7G-Tronic
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Ah, many thanks. It is the 7G-Tronic then, 7 speed.

My ML320 CDi has it too but I don't know much about them - yet! ;)

I found the following info if anyone is interested: Mercedes-Benz 7G-Tronic transmission - Wikipedia

And here, MB Medic website: You are being redirected...

I also have a 722.6 gearbox, 5 speed, in my rubbishy A160 (W168) which has a busted TCU which is inside the gearbox, currently under attempted repair. We shall see.

I'll need to find out if the valve body or TCU or both have seals to replace, mine is now 14 years old with 220,000 miles on it and I doubt they've been changed.

Thanks for your info! :)

PS: I'd forgotten it's actually 7 forward gears plus 2 reverse, total 9 gears, but the .9 means 9th generation in some info, 9 gears total in other?

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During my preliminary research I found this specialist design and manufacturing company Weistec Engineering in California:

They manufacture and fit an extensive range of upgrade parts and do refurbs for MB vehicles, including the 722.9 gearbox: Mercedes-Benz - ECU Tunes, Turbos, Superchargers | Weistec

They have an interesting info page for the 722.9 too: Understanding your 722.9 Transmission

Where I found this 722.9 service procedure document: https://www.weistec.com/forms/weistec7229servicedata.pdf

Is it in line with the info you found on ATF quantity etc?

I'm not yet familiar with the layout of this forum, is there a library section or some thread here where we can find accumulated info on the 722.9?

Thanks, as always.
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