bruceh
Well Known Member
On my Lycoming IO-320 the screws that hold the valve covers in place have external tooth lock washers that are basically threaded on to the screws so tight that I can't unscrew them. These are 1/4" screws, but the lock washer inner diameter is less than that. I'm not sure how these got screwed on there, but I'd like to replace them and I can't seem to get them off.
Cut them off and replace, or reuse them? Or is this just a Lycoming "assembly" (screw and lock washer)? Aircraft Spruce sells these Rocker Box cover screws. 24 of these are approaching $30, vs. around $1 for just the lock washers.
I have the MS35335-33 washers from Aircraft Spruce and they have a much bigger inner diameter than the ones on these Lycoming screws, and they slip on the screws like I would normally expect.
Also, is there any general wisdom on using external vs. internal teeth lock wasters? Valve covers have external, and the exhaust bolts use internal teeth (MS35333-33)
Cut them off and replace, or reuse them? Or is this just a Lycoming "assembly" (screw and lock washer)? Aircraft Spruce sells these Rocker Box cover screws. 24 of these are approaching $30, vs. around $1 for just the lock washers.
I have the MS35335-33 washers from Aircraft Spruce and they have a much bigger inner diameter than the ones on these Lycoming screws, and they slip on the screws like I would normally expect.
Also, is there any general wisdom on using external vs. internal teeth lock wasters? Valve covers have external, and the exhaust bolts use internal teeth (MS35333-33)