mylesdw, MK IV,
OOOPS!!! I mistyped???
Is that a word?
I MEANT to say (write), the Jaguar does not have a TRUE UPPER CONTROL ARM, as it uses the 1/2 shaft as the upper control arm. So it is an upper control arm and 1/2 shaft mixture. Of course, it is an independent rear suspension! My mistake for typing too fast while Sandwich is unbolting things like Speedy Gonzales. I should have paid more attention to what I was typing. The Cobra uses a plunging 1/2 shaft whereas the Jaguar uses a rigid 1/2 shaft. If it plunged then the wheel wouldn't hold up.
Kris,
I would have to see the Navy system to comment. I wonder if it is a system that is seeing loading??? The rear hub takes a pounding. Are those lock tabs used in a situation where there is not cyclical loading taking place??? Like just making sure a valve doesn't open or close? If you could describe it a little better, I would have a better idea. I suspect it is more of a case where the Navy has always done it that way and so...
You can always read Carroll Smith's book Nuts, Bolts, and Fasteners for further comment on those tabs. I encourage everyone to read it!
As for have I ever seen them fail...well, look here in the pictures I am now posting. Notice the washer was already bent. It is very hard to see in the picture, but the bearing spacer is already grooved out 0.010 inches. It was grooved out by something. That 0.010 inches has to have gone somewhere. It did. I came right out of the preload of the bearings.
As a final note...have you ever seen a lock tab on an engine connecting rod? (OK, not on an old tractor, but on a modern car?) NO! They don't use them because they don't work. If anyone was interested in keeping a nut and bolt together it would be on a connecting rod bolt. They take a pounding, but there is no lock tab to be found anywhere. The preload of the bolt keeps the nut and bolt from coming apart. Leaving a soft material under the head of a bolt or nut is just begging for it to squish out; consequently, all of the preload in the system will be lost.