Collins Russian Dictionary 2nd Edition © HarperCollins Publishers 2000, 1997:
loggerheads [ˈlɔgəhɛdz] npl
to be at loggerheads (with) конфликтова́ть (impf) (с +instr)
* is used to mark translations which have irregular inflections. The Russian-English side of the dictionary gives inflectional information.
Русский: