Figure the penetrating oil has to get past the bolt head and run down about 6" before it gets to threads.....
I second using a bigger wrench or cheater bar. I don't think I have ever heard of anyone snapping them with a bigger wrench.
If they are on that tight and need that much to break them loose, I would not be reusing those ones. They are likely to be twisted which makes a proper retorque hard to do. Once twisted, they get soft.
86/00 CJ7 Laredo, 33x9.5 BFG AT's, 'glass nose to tail in '00, 'New' frame,wires and plumbing in '09. Carter BBD Carbed 4.0 HO in '10.
89 YJ Renegade. BBD Carbed 4.0 HO. Locked front and rear with 33x9.5 BFG AT's
Some Canadian Bush Jeep Runs and Build Photos: http://mikeromainjeeptrips.shutterfly.com
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