Trying to find out how to tell what gears are in a salvaged tracker or kick without getting out the tools? And, are these center sections universally swappable btwn vehicles... the same? Can't find the answers from searching.

41 and 8 is the count for a 5.13, otherwise it's a 4.62. Tracker/Sidekick rear gears only go into Tracker or Sidekick rearends. Front Tracker/Sidekick gears will fit into either end of a Sami but sidegears have to be changed for use in the rear.

I have located a salvaged tracker and wish to find out what the gears are before I invest any time in effort. Is there anyway to tell by inspection without removing anything?

Not unless you spin the axle and count the revolutions that the pinion rotates and to throw another monkey wrench there were a total of 4 diferent gear set posibilities 5:12 and 4:62 just happend to be the more prevalant.

the more common known
automatic 2 door 4.625
automatic 4 door and most all 5spds 5.125
1989 5 speed 1.3L 5.625

there are some others with 5.38 and 4.30 but I dont know what they were in.