Step 13: Create a Seal Pressing Tool and Press Them Seals
This next step is the hardest. You need to make yourself a tool to seat the axle seals. Take your seal to your nearest hardware store and find something that will fit inside the circumference of the axle seal but is still wide enough to sit on the inside lip of the seal. For us, this was a 1-1/4" piece of PVC joiner.
The original idea, pictured first and second, was to use an all-thread metal rod (1/2") and nuts and washers to push the PVC joiners apart from the inside and force the seals into place. However, it was very difficult to get the contraption and the seals into place correctly. And once we started tightening the bolts, the washers started to give. I imagine that if we had used more washers (3 maybe..) it might have worked, but it was still difficult to get the to sit straight.
What we ended up doing was cutting the rod in half, so we had one half of the original tool, and then getting a 48" long piece of 1/2" metal pipe. We tripled the washers on the single usable end, slid the pipe through the axle tubes over the end of the tool, and hammering the seals into place. The actual tool used is the third picture and hammering into place is the fourth.