From previous encounters with design engineers (non-automotive) the very subject of replacing self-locking "ny-lock" fasteners came up. These engineers stated that the locking properties of the nylon insert were effectively trashed once they had been removed. For the equipment they had designed, they also recommended replacement once removed.
I can only assume that Honda makes a similar recommendation for a good reason.
Another rule I routinely break! I've rarely replaced them on things like shocks/struts, anti-sway bars, etc. and have never had one back off. These days the neglect is not about money, just convenience and timing, but in the old days I reused the same ones many times on my 510s and 240Z because I was always pulling them apart to try different things.
But, if you can plan ahead and get them, it's worth a few bucks for peace of mind.
KGP, to what degree do you think liability concerns prompt them to suggest replacement? They certainly aren't noticeably easier to remove the second time.
Hmmm, I guess we would have to climb inside not only the engineering minds at Honda, but also the Legal department minds to know the answer to that one! I agree, the ny-locks appear to be no easier to remove the second time around, at least nothing that my highly calibrated hand-torque-wrench can detect. I will say this: I can remember vividly when a group of "non-wrenches", including myself, were undergoing sales engineering training on a product we were told specifically that the ny-locks are not to be re-used. We all questioned "why not", and were told that they don't retain the same properties once removed. Thus, the previous response.
Jeez SJS, with all the wrench-about techno-gadget/fixit goodies that you have lying around, you mean you don't have some of these also?
Datsun 510s and 240Zs? Strange... My brother and I did the same thing with our vehicles... resused hardware 'cause, a. we were constantly making changes, b. too poor, c. pain in the but to go to the dealer. We torqued hardware to specs... never had any problems with loose hardware.
170,000 miles on a 240Z original clutch... Ya just get spoiled.