On the prop shaft there are three grease points, one at the rear universal joint at the rear as you have found and then there is another on on the front prop UJ and another on the sliding spline where the prop shaft goes into the gearbox. The front two grease nipples are under the propellor shaft tunnel and sometime there will be no access underneath. I have drilled about a 25mm ( 1 inch ) hole from which i can access both front grease nipples. I have a small tin cover to stop any crud and stones entering. There are also one grease nipple ( if you have a Salisbury 7HA diff ) on either end of the axle tubes. I do not know whether they are fitted to the BTR axle.
