2000 ML430 Auto Transmission Fluid Dilemma
 

Hello All,
I am the proud original owner of a 2000 ML430. I am seeking out some guidance and/or wisdom from my fellow ML owners.
Here is my situation:
My ML 430 has 210,000 miles, the automatic transmission fluid has NEVER been changed(as per Mercedes Service),
Transmission shifts PERFECTLY, no noises, no bangs, no slips, just like new.(thank you Mercedes quality),
However, due to age and mileage it has developed a drip from the front seal, and I am slowly losing AT fluid over time.
The level is now quite low and I need to do something about that.
I am concerned that if I add new fluid, that it will be the end of the transmission(it will start to slip)(because new fluid is clean and does not have the required dirt to keep it not slipping).
Should I top it off with New Mercedes fluid or a Lucas AT stop leak product that is thicker(to hopefully prevent possible slip by topping off)?
Your thoughts and suggestions are appreciated.

Thank You,
Dee

FOLLOW UP
 

FOLLOW UP:
I decided to add 1 quart of Mercedes AT fluid and see what would happen. I was quite surprised when the dipstick fluid level went from COLD High to HOT 'perfect level' with just one quart. I am happy to report that after 22 years and 210,000 miles plus 1 quart of new Mercedes AT fluid that the transmission is still running like new.
Thanks to all the commenters for your help !!!!