New M-B bulletin, re: 722.6 & 722.9
In march of 2003, M-B released a bulletin, advising a one-time-only transmission fluid change @ 40 k miles.
This is to remove any particles that may have accumulated during break-in.
At the same time it is also advised to change the fluid on the 4-matic transfer case?
If anybody would like to read the bulletin ( it's all in german ), here it is:
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German to English Translation:
Circular PW NR. 44/05 NFZ NR. 20/05 24.03.2005 to all Mercedes
Benz partners
Introduction of the transmission oil changing with automatic
transmissions 722,6 and 722,9, as well as with the transfer case of
the 4MATIC-Typen 203/211/220 uniquely with 60.000 km.
Ladies and Gentlemen
A substantial criterion for the customer satisfaction with
automatic transmissions is the switching quality. This not only in the
newer status of the transmission, but constantly over the entire
Lifecycle.
After the introduction of the optimized lamella package in the
transducer bypass clutch (increase of the number of grooves on 72 to
02/2004) to the long-term stabilization of the switching quality, as
well as, the oil change represents a further step to the conversion of
the NAG1 to the oil used with the NAG2 for switching quality
optimization, in order to hold the switching quality also with high
run performances on a high level. In the oil stored particle is
removed by the unique oil change, whose entry takes place to a large
extent into the first 40'000 km and it can have impairments of the
comfort of the switching quality why a unique (and not in turn) oil
change was determined.
For this the again developed transmission oil ATF3353 (AO019894503)
makes an additional contribution that we fill in automatic
transmission 722,9 since serienanlauf, with these automatic
transmissions from house. In the transfer case of the 4MATIC-Typen
203/211/220 the oil 001,989 2303 is used, in order to likewise hold
the comfort self-shadows of the 4MATIC-Systems high level with the
change.
Deviating of it a transmission oil changing with the oil FOX ATF 28
(AOO19894603), developed particularly for it, is to be executed
starting from introduction with the transmission 722,8 (Autotronic,
type 169) all 60,000 km.
For vehicles with ASSYST the service position was already taken up to
the maintenance scopes. We will extend the service pages by the note
starting from FIN XXXXXXXXX, are evident starting from WIS update
03,05 the corrected service pages. For vehicles with ASSYST plus is
caused the service position to the service page automatically by the
maintenance computer. The modification of the data records necessary
for it is only possible starting from data record release 09,2005.
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HERE IS SOMEONES FIND WHEN THEY CHANGED THE OIL IN THEIR MB 722.6 TRANS:
What I Found Inside My 722.6 Gearbox
I changed the oil and filter on my Jan 1997 C-180 5 speed electronic gearbox at the weekend and as expected the filter which fits between the sump and the bottom of the box had never been changed before. It was date stamped 8/96. Before my time with the car MB had changed the oil but clearly couldn't be bothered to drop the sump!
When the sump is dropped (be careful doing this as there is around a half litre in the sump even after removing the plug) there is a date of manufacture inside the box. Mine was made in November 96 and is number 211811. I had read that on these early 722.6 boxes one of the main bearings was bronze and can start to break up however taking the filter apart (its a small flat type nothing like an oil filter) and using a loupe I couldn't find any silver or bronze particles. In fact, despite being 8 years old and have 100000 miles it was like new. There was no sludge at the bottom of the pan only a small amount of black particles from the clutch plates.
Interestingly the filter is perhaps not designed to collect the material from the clutch pack which is what must turn the oil red to dark brown but only any metal particles. If the filter was of finer gauge I think it would get blocked with the clutch particles at higher mileage as the filter is so small.
I can see why ZF and Mercedes who make electronic boxes say these boxes are filled for life because they don't have the small passage ways that hydraulic boxes do so a calculation must have been done that the synthetic oil will still have enough lubrication properties right up until the clutch friction material wears out and a recon box is needed.See
http://auto.howstuffworks.com/automa...ansmission.htm for a detailed explanation of how automatic gearboxes and torque convertors function). However even though the oil was good in my box I did notice an improvement with new oil which rather undermines what Mercedes say. A slight further improvement occurs if you reset the adaptive memory of the boxes ECU by disconnecting the car battery.
By doing a bit of digging on the internet I'm sure the special MB gearoil is in fact Esso ATF LT 71141. This a special synthetic oil made for electronic boxes and is used by ZF in BMW's etc.The spec is the same.
One last thing reading these forums and the American versions, one might imagine MB boxes go wrong more than other makes.NOT TRUE, I looked at the claim figures on the warrantydirect site(possibly warrantywise I can't remember) and in any one year of those people making claims only 3% of those claims where for gearbox problems. In other words less than 1% of boxes of those insured needed work. Given that things like errant MAF readings can give erratic gearchanging, back street garages using wrong dextron II which gives bad changes and boy racer trashing the true figure is probably even smaller for properly used and cared for boxes. The Lexus failure rate was also around 3 %.. No one makes a better automatic box than Mercede
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http://auto.howstuffworks.com/automa...ansmission.htm http://static.howstuffworks.com/gif/...sion-model.jpg
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