Yankee-Tim, 

I installed the 2 pinion sidekick diff into my '01 and will be getting the sidekick 26 spline passenger side shaft in the mail this week.  My question is what to do about the driverside inner shaft.  It seems like it is just 1/4 inch too long now - should I have gotten one of those from a sidekick as well?  Or can the end be ground down just a bit while still retaining the spring loaded ring on the end?  Thanks again for the info.

i put the '96 kick passenger side stub axle onto my outer axle this weekend and ground down the end of the inner shaft just a little.  everything seems to fit well now.  if anybody is having problems with their air activated front diff i would highly recommend this conversion.

a new air pump from the dealer would have been $420 + tax = $450 in NJ

conversion cost me $470:

sidekick front diff (aluminum, 4.62 gears - Trail Tough) $225 + $30 s&h = $255
Manual front hubs (manual warm premium hubs - Rocky Road) $125 + $15 s&h = $140
sidekick pass cv/axle (Trail Tough) $35 + $15 s&h = $50
2 qts oil, new bolts, RTV, CV moly grease (auto parts store) $25

I actually had installed the manual hubs a few years ago to combat the oil leak problem that is common on the passenger side front axle housing so this conversion was definitely the cost effective way for me.  Plus, I know that the 4wd will always work and not leave me stranded!

The installation was not too bad, but 2 people make reinstalling the axle housing much easier.  It took me the better part of a day to do the install - but this was my first time doing something like this on the tracker.
 

one more thing - after looking at the air diff and playing with the actuator on it, i believe you could weld the actuator into the "engaged" position permanently.  this would significantly cut down on costs if you can do your own welding!

once you get the diff out you can use a bike pump to engage it and see how it works.