It may be old news to you, new to me... Here in Australia, of about 100 7.3 PSD and 4R100 Auto Trans units towing Bushtracker Vans up to 4 ton in the Outback, we have blown 7 or 8 4R100 trannys...
Now I advise them to go full synthetic tranny oil for higher temperatures preservation, increase the size of the cooler, and run to a transmission temp guage. This has worked for all but one more that did all that and still died...
I hear of a tranny mounting boost black box that boosts the transmission oil pressure about four fold to something like 80-90 psi... IS THIS FOR REAL???
It is touted in Oz to be the end all save all transmission fix for the 4R100... You Guys know about this? Is it for real?
Kind Regards from Oz....