Do your License Plate screw preventive maintenance, or end up with this:

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Dec 10, 2007
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So I go to replace the license plate screws, no big deal right?? Wrong; they hadn't been touched in years.

One screw which was likely stainless came out without much effort, just a touch of penetrating oil, but the other one had welded itself to the nut. Looking back on it I seem to recall grabbing what I had on hand, what fit, but knowing it was a POS screw, probably figured I'd replace it, but then forgot about it, 15-20 years ago. Every year just putting another date sticker on the old plate.

I first tried penetrating oil (a few different types) for a few days from both outside and inside the tailgate cavity, nope, head snapped off flush with the sheet metal.

Tried Speed Outs/Easy Out bits from outside and inside the tailgate cavity, nope. Couldn't get a straight on shot to the shaft from inside however.

Then tried the double nut method often used to remove studs, this might have worked better if I had a thinner wrench, but nope.

Then cut a slot in the broken shaft using a mini-hacksaw blade in an attempt to turn the shaft from the inside using a screwdriver, nope, ears snapped off.

Tried heat from a mini-torch, nope, started to melt the factory sound deadening even with the use of a couple of fiberglass sheets. Tried heat from a soldering iron, took the tip out of the iron and hung the barrel of the iron on the shaft of the screw inside the tailgate cavity being careful not to overheat the painted surfaces on the outside using a garden hose on mist; heat, cool, heat, cool. Nope

Tried to turn the shaft working from the inside using vice grips, not much room to work, again, moved a couple degrees maybe.

All along was constantly spraying more penetrating oil on the screw shaft. Even tried White Vinegar overnight soaked into a paper towel I stuck on the shaft in an attempt to dissolve the rust (which did work on the exposed threads). Next applied gelled phosphoric acid to the threads for 30 minutes.

Then drilled a small hole in the shaft from the outside, then a larger hole, then larger in an attempt to weaken the shaft threads hold on the nut.

Finally cut off the remaining shaft in the tailgate cavity and saw the hole I had drilled was past the nut.

All the above attempts were trying to save the original threads of the factory nut but then decided to go for broke and my last attempt I used a 5/32" drill bit into the (off-center) hole I had drilled earlier.

Heard a screeech and the drill bit went all the way through and when I looked at the drill bit on the tailgate cavity side I saw the remaining short section of threads of the screw shaft stuck on the end of the bit.

Success!!

Followed that with M6 x 1mm cutting tap to clean out the threads (didn't have a clean out tap in that size) and that did remove a bunch of rust. After cleaning the threads with acetone gave the thread/nuts a touch of primer and paint (using Q-tips) to stop flash rusting. Figure once the new screws go in the threads will scrape out most of that paint but some will be left behind which might slow down rust in the small non-contact areas.

Point is: doing some license plate screw PM could save you a few hours of pain in the arse work in 100'F+ outdoor temps when the license plate screws weld themselves to the factory nuts in the tailgate.

FWIW I'll be installing stainless steel screws (possibly the tamper resistant type) with either a thread sealer or anti-seize possibly also with an O-ring to help prevent water from getting into the threads.

Maybe these:


In hindsight (and what was suggested by others) it would have been quicker to just drill out the broken shaft from the beginning then tap both nuts to a larger thread.


Snapped off screw:

License plate snapped screw head.jpg


Attempt with a Speed Out/Easy Out from inside but couldn't get directly in line with the shaft due to space constraints (didn't get photos of multiple attempts on the broken side):

LIcense plate screw Easy Out attempt inside.jpg


Next photo shows gelled phosphoric acid on the threads attempting to dissolve the rust:

License plate screw gelled phosphoric acid.jpg


Double nuts wrenching on the bottom nut after tightening them both firmly together:

LIcense plate screw double nuts.jpg


Mini-hacksaw blade used by hand to cut a groove into the shaft. Corner of flat file was used first to start the groove:

License plate screw hacksaw.jpg
 
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Partially drilled out screw shaft:

License plate partially drilled out screw.jpg



Remaining section of threads which came out with drill bit; (double click photo to magnify for close-up view):

License plate screw threads on drill bit.jpg


M6 x 1mm tap (original thread size):

LIcense plate tap in nut.jpg


Note rust removed from nut threads:

License plate Rust in tap.jpg


Degreased, primed, and painted:

License plate painted nut.jpg
 
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LOL. I knew I might get some heat from documenting the wasted afternoon
trying to fix this minor issue but I don't like to give up easily.

The quick fix would have been to just drill out the broken screw from the beginning, tap it larger and be done with it.

However the point of the thread is not what I did to fix it, the point is to show others what happens when you ignore a simple screw that could be (should have been) replaced years ago with a stainless screw along with some thread sealer/anti-seize.

Also need to remind Wits-End (@NLXTACY) that it's time for a License Plate tamper resistant Torx screw replacement kit (screws and the special bit/tool required for installation/removal).
 
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LOL. I knew I might get some heat from documenting the wasted afternoon
trying to fix this minor issue but I don't like to give up easily.

The quick fix would have been to just drill out the broken screw from the beginning, tap it larger and be done with it.

However the point of the thread is not what I did to fix it, the point is to show others what happens when you ignore a simple screw that could be (should have been) replaced years ago with a stainless screw along with some thread sealer/anti-seize.

Also need to remind Wits-End (@NLXTACY) that it's time for a License Plate tamper resistant Torx screw replacement kit (screws and the special bit/tool required for installation/removal).
The quick fix would have been to knock the captured nut off and install a nutsert, aka rivnut.
 

mudgudgeon

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should have been) replaced years ago with a stainless screw along with some thread sealer/anti-seize.

Stainless can be a trap.

Can still rust and seize in place. And stainless screws are like butter, and gall super easy. If you think you might remove and replace the screw a few times, stainless isn't a good option.
 
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Ditto all the above.

My goal was to attempt to keep the nut/fastener method stock, and I succeeded in doing that, although it did take a few hours of working on it, something a mechanic working by the hour of course couldn't do. But then don't most of us spend a bit of extra time doing things right(er)?? ;)

Being a low torque situation that's a one-and-done application I guessed a stainless screw along with a thread sealer to keep water out might be one quick option (available at any hardware store/ACE). The screw that came out easy after 20 years was stainless (not plated) and without any signs of corrosion, the other screw wasn't. What type of stainless steel that good screw was I don't know but there are higher grades of stainless screws (316) that will resist rusting better than the cheaper stuff. And with a tensile strength of 70,000 psi shouldn't that be good enough for a license plate??



Or for those with extreme LC-OCD there're even Titanium screws available:


FWIW, for one of my other 80's I've been using the Hex/JIS screws for the 1FZFE spark plug wire plastic covers (top center valve cover), same threads as for the license plate nuts.

Either way (point of the thread) as this is an exposed screw it would be a simple PM to catch yours before they rust solid to avoid wasting an afternoon fawking with them like I did. Any new screw (along with a thread sealer or anti-seize) would be better than an old rusting one.

FWIW
 
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LOL. I knew I might get some heat from documenting the wasted afternoon
trying to fix this minor issue but I don't like to give up easily.

The quick fix would have been to just drill out the broken screw from the beginning, tap it larger and be done with it.

However the point of the thread is not what I did to fix it, the point is to show others what happens when you ignore a simple screw that could be (should have been) replaced years ago with a stainless screw along with some thread sealer/anti-seize.

Also need to remind Wits-End (@NLXTACY) that it's time for a License Plate tamper resistant Torx screw replacement kit (screws and the special bit/tool required for installation/removal).
You are a good storyteller and photo taker.
And, like in post 7, totally lucky your HG didn't blow; there IS a direct relationship between license plate screws and, well, everything else that could go wrong (see Murphy's law)
 
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"lucky your HG didn't blow"

I hope not, just finished a major engine bay refresh with all new heater/water hoses/pipes with "special" hose clamps (thread to follow), valve cover replacement along with all related gaskets, EGR valve/vacuum modulator, riser pipe O-rings, replaced/fixed cables, replaced multiple bolts, thoroughly cleaned Throttle Body and EGR gas passageway,----. Really don't want to tear back into all of that for awhile.

"I use brass screws to hold my license plates on."

I saw the brass screws available at McMaster Carr, cost around $4 each for the button head hex drive screws but much less than Titanium ($15 each!). Brass sounds like a good choice especially up north with the harsh winters/salted roads.

Metric pan head Phillips brass screws ($6 for 5):


Button Head Hex drive brass screws ($4 ea)


Titanium should also be very resistant to corrosion due to chlorine (NaCl) exposure but are prohibitively expensive. The 316 Stainless screws were affordable and I would think might last a long time before corroding (rusting) in most areas??

FWIW
 
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You might want to use security screws while you're at it:


McMaster carries stainless, button-head, tamper-resistant torx screws in metric. I used button-head hex screws, which at least requires *one* tool beyond a simple screwdriver.
I use two different types of screws on all my license plates in order to discourage theft and make it take longer.

Phillips head and/or torx/slot/hex/whatever's different and available.

I had a State Trooper talk to me one time about how I slice my annual sticker into strips so they can't peel it off. He said it's a good idea, just don't let them stack up or they are easier to come off. I told him that I knew that and I peel them if there are going to be more than two, then I told him about using different screw types as well and he thought that was a good idea.
 
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My truck sports a FL license plate which carry’s some risk because FL doesn’t have inspections and MA is a lift nazi state.

An 80 with a 4” lift isn’t welcome here.
Neither are Delicas. @dieseldog
 

dieseldog

She idles just fine . . .
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This reminds me of when I decided to change the rear wiper assemblies on my ambulance door HZJ80. Quick and easy job, right? Second bolt on the passenger side was stuck firm, and sheared clean off level with the door with barely any torque. Tried a bunch of things, but was severely hampered by a total lack of good access to the back, as it was up inside the door cavity. After wasting far too much time messing around, I said "f*** it", and took the drill to the shaft of the old bolt, driving a pilot hole by hand, and tapping a new thread over the remnants of the old bolt. Slightly different angle to the original hole, but whatever, it works, and you can't tell. The remains of that bolt are a permanent part of that door panel now.
 

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