Is there an increased risk of galvanic corrosion using stainless screws in the body of my XJ? e.g. door sill plates and other areas prone to moisture.

 

I don't know about the risk of galvanic action but I replaced all my external screws on my lift gate, headlights, door sills, and other places I could get away with using stainless steel non-structural fasteners. I also replaced fasteners under the chassis with SS fasteners.

 

I haven't had that problem, and I've replaced many. I use anti-seize (everywhere), especially underneath.

 

I also have never had an issue and every time I need to replace a nut or bolt for a part that I may have to replace or remove I try to use stainless.

 

No increase in galvanic, there will be a decrease in corrosion. Stainless threads are prone to galling under final tightening; so use an antiseize. 18-8 stainless fasteners will give you a little better than grade 5 conventional steel fasteners for tensile strength, not quite the strength of grade 8. If you have a structural or strength sensitive fastening, use a grade 8 or better (L9) with goldish zinc chromate finish. Quick blast of paint from a spray bomb to finish it off if you really need the anti corrosion. Antiseize is your friend and a favour you do for your self in future maintenance situations. For sheet metal screws I always make stainless our first choice.

 

Just think.......if the factory had only used SS bolts in those pesky rear upper shock mounts.

 

Stainless into mild steel? No - both are iron-based alloys. Have at it!

The metals aren't dissimilar enough to cause trouble (not even with the layer of chromic oxide that forms on the surface.)

 

I'm fortunate to not live in an area prone to any form of environmental corrosion. I'm about 5 miles from the ocean and even when I drive to the snow, they don't use salt in California. That means I have zero rust anywhere except for some of the screw heads which I've been systematically replacing with stainless. Just the trim, thus far, nothing structural.

I just thought I'd ask before continuing with my plan, the screws aren't cheap and I'd feel dumb if I were wasting my money. Thanks for all the info.