[Bob C]

I looked at three coupling shafts and none have grease fittings.
If you look at the torque tube there are two grease fittings, the front one looks like it would grease the u-joint the one a little farther back looks like it's for the speedo drive and the driveshaft bearing. I looked at a BB coupling shaft and it has a grease fitting but the torque tube only has one grease fitting by the bearing.