I am not sure what size bit to use for expansion bolts. Is there documentation anywhere for that? Thanks. For a 2006 v70.

On my 99 V70 with 300,000 miles, I just used 1 1/4" coarse drywall screws. I screwed them in, removed them and then covered them in polyurethane glue which expands and squirted a bit of glue in the holes. I quickly screwed them back in and the plate has been on for 2 yrs. No bracket at all, just the plate and the screws.

https://fcpeuroblog.com/blog/how-to-install-a-front-license-plate-on-a-volvo-the-right-way/

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Keeping it running is better than buying new

Hmmmm...

There are perhaps only a handful of questions for which google and the world wide web cannot provide an answer. This may be one of those questions.

Now, because I am terrible around anything plastic...

I got the bolts directly from my Volvo dealer so I can start off right. I have ordered an original bracket off ebay for nine bucks.

The question is: what size bit is used by Volvo to mount the tag bracket? How deep should it be drilled, etc.


the guy on the blog wrote "Now, comes the worst part. I used a 3/8″ drill bit, however the hole will need to be slightly larger to fit the threaded grommets. Since I apparently do not own a bit any larger, I bored out the hole using the 3/8″ bit until the grommets could be snugly popped in."

Also - does use of "3/8" automatically indicate this is the wrong answer? Wouldn't Volvo specify a metric dimension? It occurs to me to find this answer from the manufacturer of the bolt. Or maybe a page from a Volvo service manual?

Drill a 1/2" hole through the plastic bumper cover. Insert the expanding nuts that you got from Volvo. Put the screws through the plate bracket, and start them in the threads on the expanding nut. Now with your drill/driver and a torx 30 bit, run the screws in until you encounter substantial resistance. Add your front plate, there is no need to drill through the metal bumper.

Great - thanks to all for info. I realize now that the foam will be forgiving if the hole is roughly correct. I was worried that I could crack hard plastic.

The real question is the size of the expanding nut that gets inserted into the plastic bumper cover. The typical drill set will have a 3/8 drill bit as its largest size, which is why the FCP person drilled a pilot hole.

The area directly behind the plastic is foam. The hole needs to be deep enough to accept the expanding nut. Not rocket science!

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Keeping it running is better than buying new

I would drill a pilot hole through the plastic to see if there is a space between the plastic and the metal behind it.

When I added an R model bumper to one of our 850s, I found holes already made in the metal part. I did some careful measuring.

What type of expansion bolts are you using?

Most are meant to be a snug fit into the hole that you drill.

The square surfaced ones for older bumpers have a smaller portion near the surface so that they snap into a thin bumper.

The cone-shaped plastic ones with ribs fit so snug into the proper hole that they must be tapped in with a hammer.

Mollys are made to fit a certain thickness of material, I just bought some to use on a luan door - quite thin.

You could experiment with a block of wood to get a good fit.

You could also install the bolt you intend to use into the expansion fitting to see what it does when you install the bolt.

You might want to check this out. I would just use more tape.

https://www.youtube.com/watch?v=98CBaEuauJQ
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Keeping it running is better than buying new