The shaft with the grey sealant is the counter gear or more commonly known as the cluster gear. The other shaft is the reverse idler. The one with the grey sealant is the common practice after assembly. That's about all you can do. Clean them up and apply some good sealant like Permatex gasket maker. There normally isn't much more than a small amount of seepage from those shafts.
Fred


1956 3100 Pickup/Red/350/3sp OD/PS/Disc Brakes
1957 Bel Air Sport Coupe/Red/355/TH350/PS/Disc Brakes
2017 Silverado LT Single Cab SB/Black/5.3/6 Speed Trans
1947 Willys CJ2A w/F-Head engine