80000 miles 4.0 auto bought new

I ordered my jeep with an auto trans model 999. I have done rubicon trail including little sluice box a dozen times once it stopped running in 4 feet of water we towed it out and dried the dist. cap and finished the trail drove 200 miles home. I check fluid levels befor and after each trip. Oh NO the tranny was full of a mix of pink foaming water, I drain it 3 times and changed the filter. That was in 1995 today the tranny still works fine. WHY? because at 100 miles on the odometer I being a brilliant aircraft mechanic, changed all fluid to synthetic. Its the best offroad but CRUDE onroad. I still have my jeep but drive my toyota double cab 4wd trd 99% of the time. I added to my jeep ARBs dana 60 and a lot more.