tpeever said:
Does anyone have any evidence that grease really does not lubricate these bearings effectively?
If the S/Arm assembly had a grease nipple (or nipples) that actually supplied the grease
directly to the load bearing surfaces (as with many conventional phosphor bronze bush S/Arm pivot designs, then grease could work I suppose? However, if a Commando pivot is filled with grease by injecting it into the hollow spindle, then it's likely that the lubricant won't reach the bearing surfaces, all you'd be likely to end up with is a spindle plugged with grease?
tpeever said:
Reason I ask is that several seemingly knowledgeable and experienced members on the AJS/Matchy forum swear by grease, claim it does liquify enough to lubricate these bearings and obviously doesn't leak out as severely.
Firstly, I don't see any great need to deviate from the manufacturer's original lubrication specification? And after reading through the brochures of two Oilite bush manufacturers,
neither manufacturer specified any type of grease as a lubricant for Oilite, -only oil.
tpeever said:
So my question is, do people stick to oil because the factory manuals say so or because of hard evidence that grease really doesn't work?
Whatever their original reasoning behind it, the Norton factory decided that the Commando swinging arm pivot assembly would use Oilite bushes which required oil lubrication, and that appears to have been considerably at odds with the accepted practice of the day, which would have been the use of (probably) phosphor bronze bush material lubricated by grease (and the Commando manuals do specifically say NOT to use grease).
Time for a little armchair theory?:-
Oilite is porous, and readily absorbs
oil, so it does in fact contain its own lubricant, that being the whole reasoning for using Oilite as a bearing material in the first place, as I see it, as it is basically self-lubricating and also because it has good load bearing capability, and if a person were to say, for instance, add 20cc of oil to the S/A pivot, and as a result, 19cc of that oil leaked out, then they would probably have over-lubricated their pivot bearings by - 19cc ! Maybe the O-rings should also be regarded in a different way, in that they are actually there
to keep dirt and water out, rather than to keep (excess) lubricant in?
As I understand it each Oilite bearing is only going to need a few drops of oil adding occasionally, as Oilite does not need to run in an oil bath, nor does it need to be constantly "wet" with oil to work properly!
And the later (850 MkIII) "sealed for life" pivot bearings that incorporate felt oil retaining pads do seem to last a reasonable length of time without this supposed need for constant re-lubrication?
