Well… I was making good progress on removing the old adaptor plate for the 6BT engine when I met my maker with the rear seal. I am used to rubber rear seals that easily seat over the rear flange of the crankshaft. With some light lube and a gentle tap they usually go into place and while you need to try to keep them parallel with the face of the crank it usually isn’t extremely critical (when starting). The end product you do want a parallel/flat seal so the sealing lips contact the crank on all surfaces.
How am I here? I had noticed when I bought this engine and the gentleman loaded it into the truck, the rear tilted back, and a pretty good stream of oil came out. It’s good practice to replace these seals when you get the chance anyway. The Dodge variant of this rear seal is much more rigid than a Datsun’s. It’s a metal ring with a rubber seal over it. It comes with a tool to help seat the seal and set its depth (you can tap it in so far it falls into the crankcase) along with a plastic ring on the inside of the seal. Ideally this ring slips over the crank and then the seal transfers from ring to crank. This is to keep the two sealing lips from getting messed up, because it is slightly undersized to grip the crank, and you’d be trying to stretch it over the crank like a rubberband. Suffice to say the plastic ring on the Felpro gasket is the slightest bit undersized and will not go over the crank. Of course I tried to make do, and lost. When you lose you get to take the rear seal cover plate off and hammer the seal out from behind. That was a $20 mistake. I will try again tomorrow when a new one comes in and hopefully slips over the crank freely.
This is how it is supposed to go…
