It is also desirable in {HEAD ~ many systems} to maintain {TAIL ~ a difference} in fluid pressure levels between the fluid in different selected clutches, such as speed range and directional clutches, during initial engagement 
to maintain
It is also desirable in { HEAD ~ many systems } to maintain { TAIL ~ a difference } in fluid pressure levels between the fluid in different selected clutches , such as speed range and directional clutches , during initial engagement
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL 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 OTH OTH OTH OTH OTH