I find it interesting that the '90 300 CE has a torque converter drain plug, and my '91 300 SE does not (absolutely positive that it does not). Does anyone know which cars had them and which did not, and why?

Also, watching the fan turn to determine proper engine rotation can be misleading if you have a serpentine belt, in many cases the fan pulley turns backwards, using the other side of the belt for its rotation motion.

S-Class Guru

torque converter
 

You must have an after market torque converter. I have never seen a 300se W126 not have one . I have worked on about 5 in the past.
martin

I was told that my 90 300CE did not have a drain plug in the converter. So my 1 st fluid change was the tranny pan only. Next time I took time to look for it which took a while, finally found it. Check that S model good, you must have one S-class Guru

Hmmm, this gets more interesting. I bought the '91 300SE brand new, and the only time it has had any work was when I personally took the trans off last year to change the engine rear main seal. I had not been able to fine the torque converter drain earlier (there is the access port and plug in the shield) so while I had the trans out I REALLY looked for the drain plug. It just does not exists, and i can guarantee this is a factory tranny and converter, unless it got changed in the first 8 miles.
Oh well, I just drain out the 2-3 quarts occasionally and replace them, so far zero tranny issues in 140k miles.

S-Class Guru