Fixing broken bumper mount points

[rabidh]

Hi!

I've been trying to go around my (new to me, but 10 year old) Evora fixing the little niggles, and one of the issues was the reversing camera - which required me to remove the bumper.

Having just taken the bumper off I've noticed the previous owner/garage has had it off before and made a complete mess.

• On each side, the bolts securing the bottom of the bumper to the bracket in the wheel arch have been snapped off and replaced with an off-center self tapper
• On the passenger side at the top edge of the bumper, the stud in the rear clam shell that the bumper should attach to is snapped off.

Any ideas how I could fix the nicely? The snapped bolts for the bracket aren't a big deal since I can just tap a new hole and/or insert a threaded insert

However the snapped stud in the rear clam seems like a nightmare. Is there an accepted way of fixing this? All I can think is to grind it back and fibreglass in a new bolt and plate, but that's pretty extreme.

thanks!

[2011 Chrome Orange]

I have an aftermarket GTE rear bumper. As such, it did not come with the studs mounted in the bumper's rear boot /clam area. Instead, it had nuts that were fiber-glassed in place. Therefore, in that area, to mount the bumper you would simply use a bolt and washer to bolt it down to the nuts that were fiber-glassed in. Instead, I made acorn (dome) nutted studs to use in the in boot/clam opening to make them look like the original dome/acorn nuts used on the OEM Lotus bumper. (I took bolts and cut them to length turning them into studs. I then welded acorn nuts onto each one (you could probably also epoxy them) to turn them into a studs with a head or basically an acorn/dome nutted bolt. I then painted them black.)

 

So, by now you are scratching your head saying a.) what is he talking about and b.) how does this help me? Well, how I would attempt your fix is to remove/drill out the snapped stud and see if I can install a nutsert in its place. You can then use a regular bolt to bolt that fastener down or make up an acorn (dome) nutted stud like I did so it looks OEM.

[rabidh]

Thanks! Actually drilling it out and tapping seems like a good call. My only concern with that is it's in the clamshell facing out - so if I drill too far (which is kinda likely if I get to the end of the steel and there's just fibreglass after it) then I'm going to go straight through the bodywork

What I could do though is see if I can cut away a bit of the fibreglass around it and get at any extra bits of thread. If there's enough left I might be able to weld up some extra thread onto the end of a nut...

[2011 Chrome Orange]

I think I may have confused the area you are referring to... its been a while since I had mine apart.

I thought you meant one of the 5  black m6 nuts "along the rear edge of the boot aperture, clamping the bumper to the clamshell".  Do you have a photo of where you are talking about?

[rabidh]

It's what I circled in the diagram in my last post. Basically the nut that you get to at the top of the wheelarch, so a bit of a pain to get to without removing the liner. It's a different area to what you'd mentioned (near the boot) but I believe it's basically the same thing (a threaded stud attached to a backplate). 

While it's no help for figuring out where it is, I did manage to get a picture of it (attached). There's still a bit of thread on it so I reckon I'll weld some threaded bar into a nut, then screw that on (with a bit of resin/araldite). Might need a few extra packing washers but I think that'll hold the bumper on well and will be easy to remove.

Turns out on the other side the stud is still fine, but the backplate has come loose

[2011 Chrome Orange]

Ok, I think I got it now. If I'm right, the below photos shows the other side of the stud and how the plate is mounted in the pocket.

I think you have a great plan seeing your photo. The only thing I would suggest is to maybe see if you can get a die on it to clean up the threads but that may be difficult based on what is left. If your plan fails, you could still try drilling it out for a short nutsert/rivnut. But, I would definitely use a drill-stop so that you do not drill too deep and go through the body as you feared. You would have to drill through the fiberglass and metal plate.

[rabidh]

Thanks! Yes, that's it. It's really helpful to see what's on the other side.

Good idea with the drill stop - let's hope it doesn't come to that though! I'll definitely try and tidy up the thread - might be a job for a Dremel wire brush though!