I've got a 97 tracker I'm pulling the difs out of and heard that they will bolt right into the sammi axles. Has anyone done this? Do I need to change anything out?

your front 3rd member should fit in a sammie, but the rear will not fit

To be more specific.....the front third out of your tracker will bolt into the rear of your samurai (since your tracker front third will have 26 spline sidegears).  If you have a pre 88.5 samurai, you will need to redrill the tracker pinion flange, so your driveshaft will bolt up.

what about the rear third from the tracker, will that work? How many splines does the front axle have? I was thinking about geetting an adapter plate for the drive line.

no, the rear third from your tracker will not work in a sammie. its too big

thanks!

what about the rear third from the tracker, will that work? How many splines does the front axle have? I was thinking about geetting an adapter plate for the drive line.

All samurai front thirds have 22 spline sidegears.
All samurai rear thirds have 26 spline sidegears.
89-95 trackick front thirds have 22 spline sidegears.
96-at least 98 trackick front thirds have 26 spline sidegears.

If you are talking about getting a spacer for the driveshaft, so the driveshaft will bolt up to the tracker pinion flange........you can do it that way, or you can drill the tracker pinion flange to the samurai driveshaft bolt pattern, by using the samurai driveshaft end as a template (it has a "centering ring" on it so it will center up on the flange, so you can mark/drill the new holes).  If you are swapping the tracker ring a pinion over to the samurai carrier and third housing....you can swap the samurai pinion flange over to the tracker pinion gear (they are the same spline count and size).