I did remove and inspect the wing struts and mounting areas on my 150M during the spring annual inspection.
If you pulled the top strut bolts make sure they have gone back together correctly, the packer that goes on the aft side of the spar has a chamfer on it to face the spar and allow for the radius of the spar cap.
Unfortunately only one side of the spacer has the chamfer so if it goes in the other way round ( and it can ) the sharp edge can impinge on the spar radius and crack the spar. It, if memory serves me correctly it does not mention this in the manuals, but i seem to remember the picture shows it the right way round... we had a new 172R with them fitted incorrectly from the factory!
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