Swivel Housing Lubrification
By Alain Hoffmann
Check the oil level by putting the vehicle on level ground.
Turn the steering to full lock. Clean the area and then remove the 1/2inch square head bolt on top. If oil comes out it is very possible you have an inner axle seal worn. In this case the differential oil can move into the swivel. But this fault isn't very common. Feel with your finger if you can reach the level. If you feel oil I suggest all is ok. If not change the whole filling. If any oil leaked out it is very likely dirt and water got in too. To do this remove the lower plug (green arrow) and let the oil drain out. Clean the plug and replace it.
The swivel housings should contain an 80W90 or a 90W oil. A lot of older housings however loose this oil as either the oil seal is worn or the chrome swivel housing is pitted. Best is to remedy this by fitting new parts. This might, however, not always be possible.
Land Rover made a special semi-flowing grease designed for this application.
It comes in a plastic tube and has a greenish color. One tube contains exactly what 1 swivel housing needs. You warm the bag in some hot water, cut the upper part and insert it into the filling hole. One shot and it's done. But you must first turn the steering to full lock to clear the internal parts off the hole so the grease can easily flow in.
Part number is STC3435
Some guys living in colder areas have reported problems with that grease in long periods of low temperatures. If I'd live in such a part of the world I'd also keep to the usual 80W90 stuff.
If you don't want to use this grease you can also mix up a thicker oil by using 90W oil and axle grease. Thouroughly mix it and put it in. You may want to warm it up to make it easier to put inside.
Wait some minutes before replacing the plug so excess oil can drain out.