lilya76•6d agoProlific Poster

That Tuesday in Atlanta when every torque check went wrong

Last week I had a shift where three different torque checks failed on the same 737 wheel hub in Atlanta. Turned out the sealant we used was too thick and it threw off the drag readings by 8 ft-lbs. The lead mechanic Dave caught it when he re-did the whole thing with a different sealant and it passed fine. Has anyone else had sealant mess with their torque numbers like that?

3 comments

3 Comments

the_simon6d ago

@karenh56 I gotta push back a little on that. In my experience it's usually not the sealant itself but the application thickness. If you put it on too heavy it can change how the nut seats or how the threads grab. Dave's a sharp guy, he must've seen that the first round was just too much goop. That extra 8 ft-lbs is a dead giveaway the sealant was acting like a shim instead of just sealing. Seen it with RTV on some Airbus main gear once, same deal.

nathan9016d ago

Too much goop" is the technical term, I'm pretty sure. Sounds like Dave had a good catch on that one. @the_simon I'm with you on the thread seating thing, overdoing the sealant is like putting too much peanut butter on a sandwich. The nut just can't bite right, and then you're torquing it down like you're mad at it. Airline mechanics must lose their minds over this kind of thing.

karenh566d ago

Oh man, that's such a sneaky issue! We had something similar happen with a different sealant on some brake calipers once, and it drove us crazy for a whole afternoon before someone figured it out. Gotta love how something as simple as thickness can throw off everything like that!