The air chisel was essential for getting these bushings apart. Without an air chisel it is possible to saw the rubber out then carefully split the metal shell with a hacksaw but the air chisel was faster.
The air chisel was used to get the differential nose bushings out. This was also pretty hard work.
To get a lot of the performance of the solid bushings but with a much easier installation, Whiteline makes insert bushings for the differential (part number KDT925) which fill the gaps in the rubber bushings with hard urethane and use lock rings to limit the differential's movement. These give about 80% of the performance with a 4X easier install.
For the subframe, Whiteline has insert type bushings. We were running these previously. Like the diff bushings these give about 80% of the performance with a lot easier install. With our greatly increased power and much bigger tires, we wanted all of the performance possible.
The stock diff nose bushing on the left has huge slots in it that allow a lot of movement. This can allow for wheel hop that reduces traction and puts a lot more stress on the drivetrain. The Whiteline part on the upper right has some small holes to allow some compliance which is good as this cushions the drivetrain.
The stock rear diff bushing on the right also has huge gaps to allow a lot of flex. The Whiteline inserts fill these. The Whiteline replacement bushing on the left has a hard aluminum inner part which really stiffens things up. This has a urethane ring around it to allow for some movement. The holes in the urethane allow a little movement for cushioning.