Chevrolet Low Cab Forward 4500 2019 Series Owner's Manual page 285

284 Service and Maintenance
King pins (left and right)
Driveshaft splines and center
bearing (3500)
Driveshaft splines (4500)
Center bearing (4500)
Driveshaft universal joint
(Single-piece shaft)
Driveshaft universal joint
(Two-piece shaft)
Single-piece driveshaft: 2 points;
Two-piece driveshaft: 3 points
Each driveshaft universal joint must
be greased heavily until grease
oozes at the 4 needle bearing oil
seal locations. After greasing, wipe
off excess grease.