Looking for some feedback.... I have a 98 tracker 16V 5 speed with a set of 235's on in place of the stock tires & checking with some of the gear ratio caculators I come up with a new ratio of around 5.97 that going from the stock 25.5 to 29.75 with a 5.13.  I would like to try to get back close to the 5.13 & I saw in a post that the newer vitaras auto come with a 4.30 which would give me about a 5.01, has anyone tried this or has any feedback on this & will the complete axle from the vitara fit in the tracker, I can get a complete axle for under $100 & It's not worth changing the third member for that price.
Any info??

A 4.3:1 diff ratio will only make the gearing worse, not sure what your question is thou.

Whatever gearing calc you are using is very incorrect, with 31's, 5spd and current 5.12's gears I need 5.68 gears to get a correct speedo reading.

For just a simple small dia change like you have 5.38 gears would be far better idea.

But you are gonna pay thru the nose for them used as no one makes new gears.

The auto trans can use a lower R&P gear because the auto trans has a approx 1.8:1-1 variable reduction with to the TC.

The calculator that I used is from Rocky Road Offroad..  http://www.rocky-road.com/calculator.html
don't think it's wrong, but you can check it out, & perhaps give me one to try

The calculator that I used is from Rocky Road Offroad..  http://www.rocky-road.com/calculator.html
don't think it's wrong, but you can check it out, & perhaps give me one to try

The calculator works fine. If I use your numbers it says that you need to replace your 5.13:1 with (ideally) a 5.97:1 ring and pinion.  I don't get where you got the 4.3:1 or 5.01:1 from in your calculation?

Stock tires are more like 27"

OK... I see what your saying I was thinking that the calculator was telling me what my new ratio is, but not what ratio I would need to use to return to the stock 5.13....
  I was using the vitaras 4.30 in the calculator which gave me the 5.01