Changed out my radiator on my 2003 E500 Mercedes (A2115003102 replaced the old A2115000202). Just did the changeout for preventative measures. At this time, pulled a sample of transmission fluid (took sample from bottom ATF line when disconnected from radiator) and sent to Blackstone Labs for analysis to insure I didn't have any possible antifreeze contamination. I suspected none as transmission is working as designed and had the transmission fluid changed at little over 76K miles (car now has little over 81K miles so ~5K miles since change). Sample came back low in potassium and sodium as antifreeze usually shows up in elevation of these levels - which was good. However, had cautionary levels of iron and lead (386 compared to 90 average and 24 compared to 10 average respectably). Has anyone had similar results and/or explanation of why the iron and lead levels may be high. Was wondering if taking the sample directly from the ATF line when disconnected from the radiator may had contributed. Anticipated feedback is much appreciated.

 

Had to go back and remove a little transmission fluid and for 5k miles looked much worse than I would anticipate just from a visual inspection. Went back to look at the paperwork when I had the tranmission fluid changed and they charged me for 4.5 liters which is about what I'm seeing being replaced by the method of draining pan, dropping, replacing filter and replenishing fluid (around 5 liters). However, this 4.5 liters of new transmission fluid mixed in ultimately with what remained in the torque converter (few liters) and to the best of my knowledge had not been changed before, as I purchased the car when 3 years old and 41k miles. Ultimately in my opinion, 76K miles was too long to leave the transmission fluid in even though this was the first year that Mercedes was saying that it was a "sealed" unit and no need for service - I think hence they've revised there service recommendations. However, in conclusion, my belief is as the metals (lead and iron) were at cautionary levels in my analysis @ 81K miles (only after 5K miles of changing the fluid), it supports the convential thinking that the service should be performed probably every 25-30K miles to keep the fluid at optimal levels. I'm going to service again by draining @pan, dropping pan, replacing gasket/filter, and removing as much additional old fluid at the return of the radiator connection before adding new fluid. Hope to remove additional liter or so by draining from radiator connection also. My recommendation to others would be sto ervice regular (25-30K max) as if especially if you DIY it is relatively cheap preventative maintenance to extend the transmission life and prevent possible issues down the road.

 

Here's the report I got back in Jan 06 after reading about the Valeo radiator scar that finally went public.

Regards,
paul...

 

To continue this interesting thread, what are owners doing on changing transmission fluid beyond the first recommended change at 39,000 miles? Is anyone changing it at 78,000? Or some other interval beyond the first change? I think that the owner's manual states to only change it at 39,000. Thanks.

-Sean

 

Sean, originally with the 2003 E500 model I know there was no preventative maintenance schedule for this transmission (722.6). Wasn't until years later that it was modified, as I suppose that they now had data with cars with miles on them and found that their original recommendation of a "no maintenance" transmission was probably not such a good idea and the PM scheduled was changed via service bulletin to be every 60,000 KM (or ~39,000 miles) or as you state. According to information per WIS this was issued February 18, 2005 SI.00.20-P-0022-A in car models with automatic transmissions 722.6/9 also includes models 203, 211, and 220 with the 4MATIC. Hope this helps to clarify why there was a confusion regarding the service interval.

 

On my 2004 E500 owner's manual, the change interval is 100k mi. MB has changed that to 39k lately probably because they've been seeing lots of transmission failures or transmission w/ rough shifting. The tranny fluid & valve body on my E500 were changed at ~57k mi because of rough shifting between 1st and 2nd gear (all paid for under warranty). It's never too late to get the fluid changed.

 

That reminds me, I have to call MB for parts to do the Transmission fluid again this weekend when I change the coolant. I can't believe it's been 15K miles already since the last transmission oil change...

Thank you for "reminding" me. Seriously.