I saw an XJ with this cell phone holder bolted in the interior. Would this ruin any part of the XJ or cause any kind of problems down the road? I'm afraid that if I bolt anything onto the center floor area it would ruin the body and/or cause rust down the road.

 

Well, it screws through the metal so it does make a potential place for rusting. If you do this, I suggest crawling underneath and coat the screw hole area with something like silicon, rtv, or undercoating.

 

Yes, and be careful drilling those holes. The NSS is pretty close to that area.

 

Most of the mounts I've seen like this used self-tapping screws.

 

Right, but you'll have to punch starter holes in the hump to get the screws in, won't you?

 

I probably should have self-drilling, which is a subset of self-tapping. Those don't need a pilot hole, although it really helps to drill them on thicker sheet metal. But, yeah agree that you need to pay attention to what's underneath.
https://en.wikipedia.org/wiki/Self-tapping_screw

 

AH....but you're forgetting the windup of the carpet fibers when you put the screws in with your drilldriver.

 

Okay, my territory. Back in the 80s, I made my living installing cellphones and business radios. I've done everything from multi-million dollar yachts to literal junkers in the barrio. I've had my work featured in magazines. I did a few minor celebs. I think I put a phone in a Rolls for a mob boss. He and his "employees" (who watched me like a hawk and were all carrying) sure fit the stereotype. I quit counting when I got to 1,000 installations.

Most installers use self-drilling screws. They are easy, and they work well enough to get the job done. I never did. I always punched, then screwed with a normal screw. It's stronger.

With self-drilling screws, you remove metal. Then the screw threads engage the thin edge of the hole. Pulling forces on the screw tend to pull the edge UP and OPEN. Not good. The geometry is your enemy. You are relying on the strength of the sheet metal only.

When you punch, you push metal down into a funnel shape, then engage the sides of that funnel with the screw threads. Pulling forces on the screw pull that funnel UP and CLOSED, clamping down more on the screw. It's like a Chinese finger trap. Much stronger. The geometry is on your side, working with the strength of the sheet metal.

That leaves two problems to solve - the carpet and the rust.

Carpet: Spin the screw in BACKWARDS first, then run it in. Basically drill through the carpet in reverse, until you hit the hole. Now go forward to drive the screw into the metal. You will rarely have a problem that way. EDIT TO ADD: It does depend on the carpet type. Some carpets will unravel if you look at them crossways. Early BMWs! Nightmare! Some will not unravel, period. If it's a plush carpet where the fibers are pushed up through a plastic backing, you are safe from unraveling.

Rust: Lube the screw with dielectric grease before putting it in. It will coat the hole with grease. It also helps with the carpet issue.

 

I prefer RAM mounts. I've always attached them to the dash plastic. Don't have to worry about rust or sealing screw holes that way. Plenty strong for a cell phone mount. In this picture I had everything ripped apart for some corrosion treatment of the floorboards and you can see it screwed in to the left of the HVAC/Radio stack. You do need to be cognizant of what is behind whatever plastic you are screwing into obviously. I'm about to add another RAM base to the passenger side cubby hole for mounting a 10 inch tablet for nav/topo maps.

 

Why? You worried about putting a screw into a vital component? Like, say, into an A/C line? Or a gas tank?

Not that I know anybody who has done either of those....




Looks like a good setup for a modern phone.

 

On my '96 Limited, some PO just screwed cup holder & phone mount into the plastic console area...doesnt really look very schmick, but it is fairly practical !