[MBZ] OT: List wisdom re: Sub tranny flush

[Rich Thomas]

Took my 2000 Suburban 102k miles in the other day for a recall fix (fuel 
sender wires or something), they did a general inspection (to get me to 
OK them having at it $$$, no doubt).  One of the points was that it 
needed a tranny flush (burned fluid).  Reasonable enough I suppose, 
though I did change the tranny fluid a year and half ago or so.  I know 
that does not get the TC fluid out, which continues to be old stuff.  
There was a bit of discussion on this flush technique a few weeks ago, 
sounds like an OK procedure.  I am wondering though, how the tranny is 
set up -- does TC fluid actually mix with the pan fluid in some fashion 
while operating?  Is draining/refilling a time or two a close enough 
approach to cleaning out the TC?  Tranny fluid is cheap enough compared 
to the flush cost ($50), seems like it might do pretty close if just 
cleaning the fluid is the main benefit.

Thoughts?

--R