I thought torque seal was just for show until I tore down an engine last week

Finley Butler · 2026-09-17T23:00:03.740405+00:00

For 8 years I skipped putting torque seal on most bolts because I figured if I hit the spec with my wrench it was good. Last week I tore down a Lycoming O-360 that had 1,400 hours since overhaul and found 3 rocker cover bolts that had backed off just enough to weep oil. The guy who built it sealed every single fastener, and you could see exactly which ones moved because the paint lines were cracked. So the seal is not decoration, it is a witness mark that shows you what moved and when. Now I keep a tube in my box and hit every critical bolt before I close anything up. Anyone got a brand that does not dry out in the tube after a couple months?

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I thought torque seal was just for show until I tore down an engine last week | Aircraft Mechanics - SMM Buzz