Lots of dissimilar metals in the Grenadier, mostly steel and aluminum panels, screws, bolts and fittings. If you live in a marine environment or near the coast, there is a higher likelihood of galvanic corrosion setting in and causing damage over a long time period and causing screws and bolts to become frozen and seized. The best product in the world to prevent or minimize this is called Ultra Tef-Gel. It is used in the marine industry extensively and actually isolates different metals from each other with just a thin even coat. It’s expensive, however a little goes a long way. Available directly from Ultra Tef-Gel or on Amazon. I live at the beach and used it on all of my screws and bolts that hold my 2020 Defender factory Thule roof rack together so that I would be able to easy remove it from my vehicle or replace any cross rails and parts if needed. Without it, all the bolts would have seized already in the salt air. When using it, just apply a thin even coat. Be careful to not over torque as anytime you use a lubricant on a fitting it can change the torque settings. Because of this I don’t recommend lubricants on wheel studs or nuts because it changes the torque settings and grip and you can snap a stud. If there are in fact paper shims between the door panels and hinges, which would attract water and corrosion, perhaps inserting a very thin EDPM rubber sheet between them would isolate the steel and aluminum and not attract water like a paper shim might. If anyone removes a door or door hinge from their Grenadier and finds paper shims, let us all know. DaBull
