Most of the answered related questions seem to be for smaller sized TVs. So here's a similar question with slightly different condition.
I have a 85 inch TV I want to mount on the wall, so it will be 100+ lbs.
The TV mount I purchased is full motion but my studs does not align with it nicely. So the TV will be off center if I place the TV mount on the studs where they currently sit.
So my plan is to get 3/4" plywood and bolt it to the TV mount with nut and washer. Then use lag screw to attach it the plywood to the 3 studs in the wall.
The other option is to use lag screw two horizontal 2x4 into the three studs then attach the TV mount to the 2x4s.
My question is will the plywood option have enough hold for a 85" TV with full motion TV mount? Also will 2x4 in this case be stronger?
A more general curiosity is the strength TV mount on 3/4" plywood with bolt + nut vs 2x4 with lag screw?
93 lb/in
or more. This would be roughly per-bolt. The per-bolt weight carrying (Planar Sheer) is multiple times as strong. The Sheer Through Thickness for the TV is only due to the bending moment (TV weight x dist from plywood) which will be a fraction of TV weight if less than 1 foot from plywood. 3-4 bolts are fine.