diesel fumes
Registered User
had same issue with 97 f350 7.3 e4od some years back. blew out a few quarts throug seal after hauling load for couple hours on highway. had it towed home. did not pull trans or replace seal. replaced stock tiny oil cooler with 6.0 cooler ;larger iles; remote oil trans spinon filter ; larger oil pan with cooling tubes;and trans temp gauge; no problems since ; oil temp never gets above 140