W211 Transmission fluid change?

[Alex22]

Good afternoon! I have a 2003 E320 CDI with a 5 speed auto, which I bought last year. I bought it from a 'suspicious' dealer at 161000 miles, with no service history might I add. The car has been reliable, except for a failed alternator 2 months ago. Other than that, it's just been regular servicing. The car currently has 186000 miles, and I have been servicing it regularly, with oil changes every 10000 miles. However, I haven't done a transmission fluid change. I've read online that MB put a 'lifetime' fluid in their transmissions, which I find hard to believe. So, is a transmission fluid change required on these cars? Can I take it to my indie or do I have to go to MB? Again, the car is a 5 speed auto. Thanks!

 

[GordonTarling]

A transmission fluid change every 38k miles is recommended these days. An indie who knows MBs will be able to do it, but you need to ensure they either drain the torque converter or flush it through with fresh fluid. A main dealer will, of course, be able to do it, too, but I wouldn't rely on them doing the torque converter despite what they might tell you. Around £200 or so at a decent indie.

 

[grahamcol]

Welcome to the forum.
I'd suggest getting it done at a good Merc indy. My first Merc, a C200 with the 5 speed auto had its first ATF and filter change at something like 140k miles and it certainly didn't do any harm. The recommendation here is to have it done every 40k miles or so.

 

[Wighty]

If your gearbox engine bay dipstick has still got a black tab in the cap then it has never been changed . The red tab may mean it's been changed (but may mean is just been checked ) contact MB to see what history they have for the car .

 

[bob 6600]

It's done 25k in your hands with no record of it being done previously - I would just do it.

 

[Jim2]

Good afternoon! I have a 2003 E320 CDI with a 5 speed auto, which I bought last year. I bought it from a 'suspicious' dealer at 161000 miles, with no service history might I add. The car has been reliable, except for a failed alternator 2 months ago. Other than that, it's just been regular servicing. The car currently has 186000 miles, and I have been servicing it regularly, with oil changes every 10000 miles. However, I haven't done a transmission fluid change. I've read online that MB put a 'lifetime' fluid in their transmissions, which I find hard to believe. So, is a transmission fluid change required on these cars? Can I take it to my indie or do I have to go to MB? Again, the car is a 5 speed auto. Thanks!

If you uncover the transmission dipstick tube, you will see a locking tab on it, If it's coloured black, that's the original factory installed tab, and that's an indicator that the oil has never been changed,,,,if on the other hand, the tab is coloured red, that means a possible oil change at some point. As you point out, originally, the oil was "For Life", but this has changed. Unless you are mechanically minded, it's better to have a mechanic check it out for you. He can dip it and the colour will tell a lot about uf or not it has been changed.