1996 Jeep Cherokee (automatic) slow 2nd to 3rd shift when cold

Would this kick-down cable the same as what we used to call a passing gear linkage (seems like they used to have them on older auto trannys and they were adjustable). Is there any way of cleanig them? Also the tranny fluid on the dipstick seems to look relatively clean, would replacing the filter & fluid do any good?

I went ahead and sprayed the cable near the throttle body with some penetrating lubricant (some stuff we use at work) on the wire part where it goes into the insulation part of the cable. The other end of the cable goes in above the tranny into an inaccessible area. My daughter drove it afterwards and it seemed to be shifting OK (mind you the Jeep sat just for a few hours and the outside temperature was around 50 degrees.) Would it take a few days or longer for the pen-lube to work its way down the cable to take full effect or is there anything else I can do in case it doesn't? Also it seemed when I was working the throttle the cable seemed to act like it had a bit of slack where you could manually move some of the wire back into the insulation (about 1/2 inch or so) after the throttle was disengaged. Thanks.