had to try this mod. for rigs with < 3" it is supposed to help protect the re-occurring failure of the inner boot. My first try doesn't seem to have been quite right as the boot is showing a concave wear line after only few hundred miles back on the road. OEM boot kit 04438-04021
steps-
cut old boot off but retain the outer, small end of the boot. the rubber ring will be reused as the spacer for the mod
remove old grease
remove snap rings on the tri-pod bearing then slide off the spine. You can drift these, I used a press. some models , like this one, have 2 snap rings. 1 on each side of the tri-pod.
remove the remaining boot ring and clean the axle, trim ring to a 1 - 2 in wide ring (mine was an inch and the new boot ribs still rub, so I am going to redo with a 1.5 to 2 inches of spacing).
install new boot, spacer, snap ring below the bevel on the axle
install new grease and clamps (you need a spare larger clamp for the outer small end of the new boot. the mod moves this to a wider part of the axle)
reassemble into hub and differential.


here you see mod; in order the axle bevel, the snap ring, modified boot spacer and the new boot








shows the wear groove, last rib of the inner boot still with the mod spacer









position of inner boot ribs on flat ground with the 1" mod spacer. Can see only 1 or 2 mm space.







shows the wear groove, last rib of the inner boot still with the 1" mod spacer after about 400 miles



bevel, snap ring, spacer, new boot







tri-pod bearing after pressing the axle out