Davel

MB states that the 722.6 tranny and differential are both lifetime fill, unless a leak occurs. However i just read an article that states: " all transmission 1996 and later fluids should be changed every 30K to 40K miles, Lubed for Life is about 80K to 100K miles and he has seen a number of trannys with sludgy, dirty fluid at 80K miles, and MB recommends replacement of the tranny at this time if there is any problems. Wear metals such as iron and aluminum originate from machingi during manufacturing and silicon comes from sand left over from the casting process and can only be flushed out with periodic fluid changes. MB in 2006 now recommends fluid changes around 35K miles"

I have a DIY session coming up at a local dealer so i will change mine at 44K it will be interesting to see what the old fluid looks like. The procedure is fairly easy on the 5 speed the 7 speed requires a machine...

SAguirre

The term "lifetime" is very relative term and has a lot of interpretations. There really is no such thing as lifetime if the use conditions are severe or if unusual things happen.

I personally got a $300.00 Amex. certificate from Mercedes last summer (I think it was then) and I used it to have the transmission and all three differentials flushed. My car only had about 25,000 miles. I did not have the fluid tested, but I am sure that I can now drive with peace of mind knowing that all the break-in debris are out of the fluid and that the filters are clean (in the tranny). I expect to change it again at about 100,000 miles.

Another important issue is that I don't believe that the engine coolant is as "long-life" as they say it is. I just test the PH, if it goes anywhere near 8, I change it immediately. If you don't, then you can expect the plastic necks of the radiator and other parts to become brittle and fail.

I only do this because I keep my cars for a long time. My E is just about to approach the 4-year mark and 35,000 miles. It is running perfectly and I intend to drive it for a long time. I will be replacing my Audi S6 (which is now 12 years old and in perfect condition) with another Mercedes when the Bluetec comes out on the W212. I will keep my 4-Matic for the winter times. Overall, I always change fluids as a preventative measure and I have had great luck! As far as the oil goes though, I do trust the synthetic oil and I have been proven correct by the lab test. I drive about 8,000 miles on one oil change.

This is just my opinion though,

Steve

Davel

Yep i agree, plan to keep mine for a while too, so i consider it cheap insurance in the longer run....

chairman

is nothing more than an excuse to lower TCO (total cost of ownership) claims by MB and other manufacturers.

Cheap insurance is 30k changes. If the fluid goes too long it will become burnt and turn to varnish, and that is when problems start.

I took a Nissan to 160k with regular oil, filter and trans fluid changes. (the car was totaled in an accident) I had someone drop the transmission pan at around 140k (to change the fluid) and he remarked at how clean the fluid and the pan were. I am a true believer in preventative maintenance.

jimbo1mcm

My dealer finally got a BG machine to "flush" the tranny fluid. Actually "flush" is a misnomer. The fluid is exchanged. It takes about 15-16 litres for the process. This is required because the fluid in the torque converter cannot be drained. I have it done every 35,000 miles. Cheap insurance.

vettdvr

I change my E500 tranny fluid at home. It is not that difficult. I do not flush but remove the pan,, change filter, fluid and gasket and use only MB parts/fluids. I realize there is the other view that this leaves 1/2 of the dirty fluid inside. I however have been doing this since 1964 and never had an auto transmission failure with most driven over 200000 miles. The only tranny failure I have has was under water for Katrina. Didn't have time to drain/flush it had to be driven. and later failed with water inside.
But I would recommend changing. Our E500 fluid change was at 70,000 miles and was relatively clean with nothing in the bottom of the pan that could not be wiped out with 1 paper towel.