scott suhring wrote:
>
> Gary Oehrle wrote:
> >
> > to all
> >
> > Sorry, but I have a hard time buying this one--Grease drying out!
Strictly speaking, it is true... most chassis greases are a barium-soap
base, or something similar, and are therefore water-based. The soap is
a surfactant, so it tends to bind the water and organic materials
together. Really, really old grease is quite hard, because there's
nothing left but the soap, a few organics which are thick enough not to
flash off, and a little bit of fiber filler.
> > I redid from trunnions, '74 TR6, and the grease was still healthy.
I would guess, then, that it was regularly greased. Properly greased,
the old grease is forced out by the fresh grease.
> > These things are lubricated via grease nipple, right? Or am I missing the
> > point in the use of the word oil.
I would guess, somewhere in the world, there's a Churchill tool made to
pressure-lube trunnions.... <g>
I think all the talk thus far about the trunnion being a special
Archimede's spiral (technically speaking, an Archimede's spiral has a
constantly decreasing radius, I think, and that's not what's in there)
and that it pumps oil around as the suspension works up and down is
probably wishful thinking. In fact, it's an Acme screw thread, and is
used because it has sufficient load-bearing surface for the loads
imposed with less slop than a typical USS screw thread. Probably EP 90w
oil would give better lubricant distribution than grease, if properly
filled, and the trunnion seals were good. But I think the real point
about 90w oil and trunnions has to do with the materials--since the
bronze used for the trunnion is mostly copper, a water-based grease may
cause some corrosion on the bronze, which would accelerate wear.
> As this discussion as progressed, one question which I have not seen
> brought up. What do you do if the trunnion has been greased and you
> want to correct this with using oil?
Well, one could take them apart, clean them thoroughly in solvent, dry
them off and reassemble with oil (probably the right way), or one could
just start pumping in oil at more frequent intervals than is suggested
in the manual, and eventually flush out the grease. <g>
Cheers.
--
My other Triumph doesn't run, either....
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