4th gear slips (revs to5500 then engages)
 

Just put in used tranny shifts great 123 sometimes 4th slips then catches .put lucas trany slip in when I put trans in.no codes or lights ? 94 accord

New clutch with the trans?

(or is it an automatic??)

check for malfunction solenoids

It is automatic and only does it when its cold.after you drive for awhile its fine.I have put lucas automatic trans slip in and no help.I do have old trans and solenoids which one can I try ?

Check for trans codes by shorting service check connector under glove box and reading flashes of D4 light.

Download 94-97 Accord manual from Online Manuals post in DIY forum for key to codes.

Also if no TCM codes, then check hydraulic symptoms chart in shop manual for clues to rpm flare w/ 3-4 shift.

good luck