Hi Guys,
Here's the report from the Blackstone Lab 197,823 miles on trans. 4R100, 9,911 miles on trans oil and filter since last change:

Iron read was high again in this sample. Though it is hard to say if this is a major concern or not considering that alot of the previous oil was still present in this sample. With all other wear indicators looking good, we doubt any serious problems are creeping up, though we think it was a good time to change the oil, at least as much as you could get out. Insolubles show that the oil filter was used up, so hopefully that it was changed at the same time as well. If it was, we think that this unit is going to be ok, though we do recommend that another fluid change be done in 10,000 miles.

Now, since the TC doesn't have the drain plug and Ford (and other shops) will not complete a full fluid exchange only the pan was drained and sample taken. The mentioned filter was from AAMCO and I was surprised that it was used up within 9900 miles. Based on what the oil report said, I'll do a complete flush this week with Ford filter change and run 10,000 miles and have another oil test done.

I guess my point here is that it's difficult to find a shop that will do the complete fluid exchange and that AAMCO filters are not a quality filter. I read somewhere here ( I think) that Ford doesn't recommend changing filters on these transmissions. Based on the Blackstone report, transmission filters should be changed out regulary. What do you guys think?

My question now would be should I use a synthetic fluid or continue with Mercon?

Jeff