Transmission Service at 100K??

No... don't follow that 100,000 miles... that is a recipe for disaster...

Tiger, Could you elaborate on why you say this is a "recipe for disaster" please? I have a '99 e430 and I am contemplating a transmission service. No performance reason, however since I cannot see and smell the transmission fluid, I get nervous.

The ATF fluid can last that long because it is synthetic. But the filter cannot last that long and so much sediments from clutch plates will simply overwhelm the filter. Once the filter is clogged, it will simply bypass and let the saturated ATF with sediments flow through... Like dirt in oil, it will wear down the engine. In tranny, it will start to wear those electronic valves and all mechanicals inside the tranny.

I got a BMW with lifetime fill tranny... I drained it at 115,000 miles because my tranny cannot move anymore... and I looked at the fluid... I can't believe it... so saturated with sediments and blackish. It cooked my valve body... so once I had someone rebuild the valve body, tranny is just like new again.

With regular fluid drain and filter change, tranny should last anywhere from

160,000 miles to up to 290,000 miles depending on how you drive the car... city will get low end, and majority highway will get high end.

Tiger, you echo my sentiment exactly.

Did I misunderstand you?

What service interval would you suggest for a "lifetime" fill tranny? I was thinking 100K but perhaps sooner? I have about 60K on it now. My driving is moderate, not much "around town" because I live out in the country but low mileage (less than 10K a year)

Synthetic fluids can be expensive but you are not completely draining the system... merely replacing like 3 or 4 quarts. With this in mind, there are still 8 quarts of olf fluids remaining roughly.

The key point is FILTER change... so I'd suggest every 30K to 40K miles... go as much as 50 if you want... even at 50K you are doing twice the recommended fluid change. If you are over that, well just do it.

There is no guideline but if you just think about it. You are reducing the sediments from clogging up the filter... you are providing new fluids with additives that prolong the life of remaining fluid and parts in the tranny.

This is also cheap insurance... price out a filter change service compared to rebuilt tranny R&R cost. There is no comparison as these tranny are getting close to $5000 to R&R.

I haven't seen the torque converter on a Benz newer than 10 years old, but those I have seen have a drain plug so almost all the fluid can be removed.

Tiger,

Thanks for explaining the need for Mercedes transmission filter replacement on 30 to 50 K, much sooner than 100K as recomended by Mercedes.

Yes. Thank you.