This is the tool I machined to insert the seals into the front knuckles on our GMC with the axles in place. It can also be used when the knuckles are off the coach as well.
Just a simple tool, that has worked well,
twice for us.
Drawing dimensions are in inches. This clearance allows plenty of room for the shaft, when you place the seals without removing the knuckles from the coach.
The tool puts the seal into the proper position and seats it with a slight tap with a mallet without any chance of bending it or twisting.
The material is a piece of Nylon rod.
looking through the tool
Bill Brown's aluminum version of John's tool
Bill Brown of Coshocton, Ohio