I have a 1990 350SDL with 180,000 miles. I have owned it for 15 yrs. It had factory rods bearings and head gasket @ 75,000 miles. It has been meticulously maintained by a Indie that worked exclusively on Mercedes. He recently passed away and the shop closed after 50 yrs of service. I have never worked on my Mercedes and really don't want to begin. I have searched unsuccessfully to replace him within 100 miles. I currently am due (30,000 miles) for transmission service. The fluid looks new and transmission functions as new. He used Mercedes ATF and Coolant in his shop.
It is not a primary vehicle and I put 100 highway miles on it every 2 weeks. It is garaged. Given my circumstances I would like to have this service performed "once and for all".
I called my cousin. He is a GMI grad and has been top metalurgist at Allison transmission for 30 yrs. He told me to drain and change the filter and fill it with Mobil Delvac Syn ATF and forget about it. This is a fluid developed by Allison for heavy transmission M1 tank etc. His opinion is with 4000 highway miles /yr the transmission will safely service another 100,000 miles with no additional service. I'm 62 and it will probably exceed my lifetime.
Disclaimer. I have read every ATF thread on this site. Please no flame throwers just wise council
