Originally Posted by To_fire

Hi and great work on your 4r! You may also consider removing all 3 of your skid plates and spraying what they hide above them. Also, there's a small cover panel about 1/2 way on the left frame rail (below where the driver's door and rear door meet). It covers a small proportioning block and those flare nuts rust out quick. It's 2 10mm bolts. I had my guys also spray my driveline bolts and exhaust bolts. If you can get help from your son, remove bolts and coat them with anti-seize/oil. Same for the oxygen sensors. Makes them easier to remove when time comes to replace things. Also spray the spare tire mechanism, chain and bracket. Make sure the 2 breathers at the rear axle are clear and/or re-locate them. You can also replace the non-torque sensitive zinc bolts with stainless flange bolts. Krown and Rust Check are basically the same formulas. They started out as 1 company, but the owners had a disagreement and split into 2 companies.