I've been driving my '65 3/4 ton with the original 3-speed-with borg warner overdrive since I bought the truck in 2015. I've really enjoyed the uniqueness of the setup, but I miss the low gearing of the SM420, and I plan to swap transmissions very soon. I want to replace the front and rear seals on the SM420, but I've heard the rear takes extra care so as to not have bearings fall out or what not. Is it a straight forward thing to do? I searched on here about replacing the rear seal, and I saw some have done it, but I didn't find any info on actually changing it, just info on slingers and no-slingers on the front shaft. What is the procedure to replace the SM420 rear seal? Thanks.
