I purchased a SM 420 transmission from a local with the intention of putting it into my '49 half ton. It had that preservative tape wrapped around the spline shaft and looked as if it had been stored inside for many years. However, when I pulled the drain plug, the first thing that came out was about a pint of water. I removed the inspection plate and I can see some surface rust on the lower part of some of the gears, but no broken teeth, no metal shavings and everything turns as it should. My biggest concern is potential water damage to the bearings, but the water was at the very bottom of the case.
Should I roll the dice and install it as is or should I bite the bullet and have it rebuilt?
