How To: C15a Wire-3 restoration

[Grant Bowker]

Possible problems with sealed bearings:
Fully sealed, you will be relying on the grease within the bearing only, no transmission oil will get in, so new oil in the transmission only helps the gears, same old lubricant in the bearings.
Sealed one side (outer face), solves the issue above but no lubricant reaches the original style seals to help them slide on the shaft so they are likely to have a shorter life.
My choice would be new seals, separate from the bearing, running on original shaft (as long as it shows no grooving). I forget whether the gear clusters are one piece or pressed onto the shafts. If they are pressed assemblies, adding speedisleeves to repair scored shafts could make them difficult to take apart if you ever need to separate the cluster. But on the mileage we do on restored trucks what are the chances of that?