After years of lusting and coveting (I have found the best cure for lusting and coveting is just to go ahead and get), I finally snared a NOS set of five genuine real Emergency! Squad 51 Chrome Diecast Cab Lights to finally get rid of the short-lived fading cracking leaking awful-looking even when new plastic ridiculous joke for cab lights that came original on the truck.

I already ordered - be here later today - a box of 100 oval-head stainless #10 1-1/4" sheet-metal screws.

Then, since, unlike the originals that require the entire thing be unscrewed and removed to access the bulb and have to be sealed and siliconed all over again. these are pretty much permanent mount in that the lens is held to the base by it's own screw, completely independent of the base screws; I got to thinking something more permanent and reliable would be in order.

RivNuts ----- I don't have a tool, but have my eye on one that has me lusting and coveting all over again.

I already have a box of stainless 10-24 oval-head screws.

What are you guys thoughts on using Rivnuts under the cab lights instead of simple screws through the thin metal ?

Is there a disadvantage to the RivNuts that I am not seeing ?

I am so proud of these new-to-me cab lights.

Compared to the silly plastic originals, these things are MASSIVE; one weighs more than three complete sets of the originals.

Standard delivery is a single #67 incandescent bulb; same base as 1156.

I have a big bag full of T10/194 pigtails and some insanely bright durable T10 Amber LEDs.

I easily removed the #67 bulb and it's guts from the light; in fact, so easy that people probably handle the light minus the bulb and lose their guts.

I first thought maybe a single T10 LED; but then, I got to looking at that massive cavern under that big Amber lens and thought "if one is good, two will have to be better"

It is amazing how well they fit under there and it is ABSOLUTELY AMAZING how insanely BRIGHT they are.

I bench-tested side-by-side, a light with the as-delivered #67, one with a single super-bright T10, and one with dual T10s = that twin-bulb configuration is WICKED and the way I will go.

I let them burn for about five minutes and then felt of the lens; the two with LEDs were cooler after five minutes out in the unheated shop than they were in the house with no bulbs at all; the one with the incandescent #67 could have been used to keep your supper warm.

So, which is it, screws or RivNuts ? Thanks.

 

I used blind sealed riv nuts when I installed mine. Somthing like this.
https://www.mcmaster.com/products/ri...nd-rivet-nuts/

 

Definitely riv nuts, provided the flange won't stick out past the fixture. Don't forget to dab some sealant under the riv nut flange. I generally use stainless riv nuts for exterior work. Also be sure the fixture gasket is soft enough to seal over the slightly raised flange. Worth testing on scrap first cause the riv nuts need a big hole.

 

Thanks; I was not aware that such an animal existed.

I learned something else I hadn't considered from reading through the McMaster-CARR page = thickness of the target material is a consideration when choosing the nuts.

 

Thanks.

All very good advice considering I never set a rivet-nut in my life; especially the bit about practicing on the barn wall or a barrel lid or something before jumping in head and ears.

I usually just jump in head and ears and learn my lessons the unforgettable hard way; but, maybe the top of my truck cab is not a good place to fly in on for a first-timer like me.

 

I dont like rivnuts because they often sieze on the fastener, and then spin in the hole theyre set in.

I have seen some factory cab lights use the threaded clips instead.

 

I got a tool with a handful of aluminum rivnuts at Harbor Freight but don't use the aluminum ones. Get some cad or zinc plated steel ones and use them instead. The aluminum ones will corrode and seize up.

 

Rivnuts are excellent, but as noted can spin if the screw gets rusty. Try to get the type that has a locking key or tab which when installed in the correctly drilled and keyed hole will not spin later.
Also suggest that use use anti-sieze grease on all the screws that go into Rivnuts.,

Here is the tool to make the holes:

https://www.rivetnutusa.com/install-...0-key-seating/

 

That is a good point; actually, I have had that happen on a few things over the years and it is sometimes quite the chore to get things apart when this happens.

I am a firm believer and heavy user of "You and your old silver ****(excrement)" ---- (are you reading this Levi?); I often have it dripping off my elbows; however, it seems like I may be their only customer according to the amount of froze-up stuff I have had to deal with over the years.

Once these cab lights are installed,those screws will probably never ever be removed again; however, it might be good practice to periodically remove them and add another dose of anti-seize.

Curiously, I thought it was always "i before e except after c"; I typed anti-seize and then looked at it and thought maybe I should switch the i and e, and did; and, spell-check red-lined it as wrong; so, I switched it back to ei and it accepted that, forever shooting that i before e business that had been driven through my skull in school (12 years of my life that I will never get back) out of the water.

 

Thanks for that; I was not aware of the non-spinning type of RivNuts.

 

After 40 years in aviation maintenance, I can tell you the reason why they spin is because they were incorrectly installed and the reason why they seize is because someone didn't use Anti seize on the screw. The hole has to be a very tight clearance, a friction fit. If it drops straight in the hole you have already lost. Use a sealant like Flamemaster B 1/2 or the like on the rivnut during installation. Do not use silicon. Let the sealant cure then use the anti-seize of your choice on the screw.

 

Thanks for this wisdom.

Just how snug must the hole be, considering that I cannot support the backside of the cab roof and much force will likely cave it in ?

Besides having a tight fit, what other things must I attend to for a good installation ?

I figure to make a few practice runs on the side of the clothes dryer to determine proper hole size; and then, put a bit of torque on them to see how well they hold.

Do I apply the sealant on the RivNut prior to inserting/seating or after it is set ?

 

The corollary to the old mnemonic rule of thumb is "or when sounding like A, as in neighbor or weigh" but that still doesn't work for your situation with "seize" so I guess that falls under "for every rule there is an exception"...

All this may be a moot point once the wife sees her dryer door sporting LED clearance lights anyway.

 

A slip or drag fit. Just a little tension to push it in. I use an undersized drill then adjust it with a tapered ream.
Apply the sealant to the outside of the rivnut sparingly before installation. You don't need a lot. I remove the paint around the hole to assure a good bond.

Remember, these are not pop rivets. If you pop one, you stripped the threads out of it. Also, they are not meant for structural support. So "just snug" is good enough for the screw.
With a little practice, you will get proficient with it.

 

Cougar is correct about the size of the hole and I should have mentioned this. If you try to install a Rivnut into a sloppy hole it is game over before you even start.