Reuse bottom end nuts and washers?
 

Is it safe to reuse the m12 and m10 nuts and washers, or should you replace them for safty's sake? The manual does not mention anything.

Reuse. Reuse flywheel bolts, too. Replace connecting rod nuts.

I've reused with no issues.

I don't know if the bottom end hardware can be affected like the head hardware, but I've seen galling on used head nuts and washers one time - I sanded them smooth with (I think) 220 sandpaper. Is this practice OK?

I think your only issue here is removing the zinc plating, and now you have more potential for corrosion.

There are certain fasteners that either stretch too much (aftermarket head studs) or have the risk of stripping the head (like a cam sprocket bolt or CV bolts) or can have the locking features worn smooth (like a rod nut or lock nuts, like on the front strut attachment bolts) - so that's why you replace them.

Say what? I thought the flywheel bolts were one time only.

I would not feel comfortable reusing those end nuts and washers.

The reason I asked is because looking at some tables the friction changes a lot depending on what finish the hardware has. Wear changes/ removes the coating and could change the initial stretch done with the torque wrrench. I will make sure the zink is still there before I reuse them, but it is encouraging to hear that others have reused without issues. There are enough things to throw money at on this car....

Van, is this something you do regularly?

I've done a number of engines reusing the girdle and head washers and nuts, and haven't had a problem. I do always oil the washers/nuts for an accurate torque, and I pay attention to the "smooth" side of the nut to mate against the washer. If anything is galled or doesn't thread on easily, I throw it away.

For the flywheel bolts, I've had the discussion with Michael Mount, and he agrees that they can be reused.

Good to hear. Thank you.

Thanks, Van. I oil the nuts and washers every time as well.

Hm interesting. I've got a pile of "used" flywheel bolts from my previous endeavors. I save all my old bolts and nuts, but the flywheel ones don't seem to have too many other uses.