If the balance shaft is mounted in roller bearings and if {HEAD ~ the roller bodies} have {TAIL ~ direct contact} with the bearing surface, it is implemented in a suitable steel and the bearing journals are hardened 
If the balance shaft is mounted in roller bearings and if { HEAD ~ the roller bodies } have { TAIL ~ direct contact } with the bearing surface , it is implemented in a suitable steel and the bearing journals are hardened
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH