Does my 1998 4 door 4wd jimmy have a trans cooler?

Yes ,its on the passenger side inside the radiator .(if you have one) You will see to steel lines coming out of the radiator one at the top and one on the bottom I beleive the top is your inlet and the bottom is the return line

The trans cooler is in one of the radiator tanks.All automatics have this.Some vehicles with the bigger motors and transmissions will also have a separate cooler.Some people will install a separate cooler in there vehicles when they do a lot of hauling or trailering.Hope this helps.Good luck.