1999 ram 1500 5.9 auto 107000 miles. I got my oil changed at the local valvoline shop and I saw the "tech" top off the trans fluid. I asked him what kindof fluid it was he said dextron ATF. I know the trans takes ATF+4. Will the half a quart of dextron damage the tranny? Should I dump and flush it? Thank you in advance for your help.