Door Loop Repair (Rivet nut / Nutsert question)

[Fulton_Hogan]

I'm needing advice on how to proceed with drilling and adding rivnuts/nutserts to get footman loops back on a pair of doors.

Whoever previously owned them stripped or broke the original bolts for both doors' door strap loops. On the passenger door they drilled out new holes. The ones on the driver's side still somewhat work. I'm plan on redoing them anyway.

Here's the passenger (worst) door:

I thought I'd drill out in the location of the original holes since they're somewhat where new rivnuts/nutserts should insert.

However, feeling on the backside/inside of the door, there's another piece of metal with extended tubes for the original bolts. I don't know if that part will get removed when I drill. If is doesn't come out I figure the rivnuts/nutserts won't crimp properly.

As to the rivnuts/nuterts what size should I bump up to; 1/4", 5/16", 3/8"?

I know I'm not the first person to deal with this. Hoping someone here can help.

 

[GregBelleville]

I'm needing advice on how to proceed with drilling and adding rivnuts/nutserts to get footman loops back on a pair of doors.

Whoever previously owned them stripped or broke the original bolts for both doors' door strap loops. On the passenger door they drilled out new holes. The ones on the driver's side still somewhat work. I'm plan on redoing them anyway.

Here's the passenger (worst) door:

View attachment 506306

I thought I'd drill out in the location of the original holes since they're somewhat where new rivnuts/nutserts should insert.

However, feeling on the backside/inside of the door, there's another piece of metal with extended tubes for the original bolts. I don't know if that part will get removed when I drill. If is doesn't come out I figure the rivnuts/nutserts won't crimp properly.

As to the rivnuts/nuterts what size should I bump up to; 1/4", 5/16", 3/8"?

I know I'm not the first person to deal with this. Hoping someone here can help.

I just stripped out one of the bolts on my driver's side handle this weekend, so I'll be following along intently.

 

[C.J. Roberts]

I think that you're just feeling the barrel of the rivet. If there is a backing plate, you can just fish it out and clean up the holes, then reuse it. And there isn't any reason to not use plain old screws and nuts if it's easier. Maybe use a fender washer to back the nut for reinforcement.

 

[Fulton_Hogan]

After putting off drilling out whatever the previous owner tried to do to these doors (other than make holes and mar paint), I finally got the nerve to drill.

I started with the passenger door because it was the worst. I thought it would be a pain (for me) because the barrels on the backing plate both bent in different directions and the bottom hole had a lodged-in broken screw. (See this thread's original post.) I used a small bit to get started, working my way up about two more bit sizes. Once I got deep recesses in the holes I tried a step bit.

I used an acorn grinding stone on my Dremel to remove more metal. Using it also gave finer two-hand control than the drill. I went back and forth between the drill, its bits, the Dremel, and its grinding stone several times because I didn't want runout with any bits.

I went slow and frequently checked the backside to see if I'd removed enough metal to break off the barrels. When they finally broke free I used a carving bit (probably not designed for metal, but it worked) to remove any burs. A couple hits with the step bit and a few runs with the grinding stone at an angle from the front side made it possible reach the backside, and I had them smooth pretty quickly.

The driver door was much easier, neither barrel was bent. I was able to just run the step drill in each hole until until the barrels broke loose. Then I did a couple quick passes with the Dremel. Again, carving bit first to get the backside burs from the front side, then the grinding bit to smooth out the hole .

Here's the aftermath:

Right (Passenger):

Left (Driver):

Next step, figure out what size rivnuts and which tool to buy/use for the task.

 

[Fulton_Hogan]

Follow up question:

Has anyone used M6 hardware to mount their footman loops?

I believe the holes drilled on my doors are just undersized enough for stainless M6 rivnuts.

Current holes are about 7.9mm; the M6 rivnuts need 9.0mm. I can file/grind/drill to get there. (What I can't do is add metal back.)

What I'm trying to avoid is going too large with the mounting screw that they won't fit through the footman loop's holes. I believe M6s should be good since they're only 1.2mm larger (6.0mm) than the original #10-24 (4.8mm) screws.

If you've used M6s to mount your loops, please let me know.
If not, what did you go with?

 

[mrblaine]

Follow up question:

Has anyone used M6 hardware to mount their footman loops?

What size anyone has used is determined by the holes in the loops. The original are 10-24 or so and you're moving up to what is effectively 1/4"

I believe the holes drilled on my doors are just undersized enough for stainless M6 rivnuts.

As long as you can get a 1/4" or 6mm screw through the hole in the loop, it will be fine.

Current holes are about 7.9mm; the M6 rivnuts need 9.0mm. I can file/grind/drill to get there. (What I can't do is add metal back.)

You actually can, just not as easily as going to a larger nutsert. If you examine the door a bit more intently, you will see two spot welds between the holes. The factory made a nutsert plate, lined it up under the two holes in the door shell and then spot welded it in place. The door shell holes are slighly oversize for them to have some room to line them up to a fixture and get them all in the same place plus the plate acts like a fender washer to add some strength to the thin door shell.

What I'm trying to avoid is going too large with the mounting screw that they won't fit through the footman loop's holes. I believe M6s should be good since they're only 1.2mm larger (6.0mm) than the original #10-24 (4.8mm) screws.

If you've used M6s to mount your loops, please let me know.
If not, what did you go with?

Just find a 6mm screw and test fit it in the loop holes. 6mm is .236 and 1/4" is .250 if you can't find a metric screw. I suspect there will be some issues.
It is also possible to duplicate what the factory did with another plate, back it up to the one that is there, bolt it down with the footman loop, and then rivet it in place with some 3/16" SS rivets. You could move those out to just past where the door panel opening is cut around the loop and hide them easily.

Last thing to be aware of to check is the vast majority of metric flat head screws are 90 degree angle for the countersink. The vast majority of SAE flat head are 82 degrees so the contact in the countersink will be different.

 

[Fulton_Hogan]

@mrblaine I appreciate all this.

I'm checking in between paint coats, so I'll be able to respond more later, but all this is excellent info!

Taking the loops to Ace Hardware and test fitting screws was my next step.

Again, thanks very much!

 

[Fulton_Hogan]

What size anyone has used is determined by the holes in the loops. The original are 10-24 or so and you're moving up to what is effectively 1/4"

As long as you can get a 1/4" or 6mm screw through the hole in the loop, it will be fine.

Just find a 6mm screw and test fit it in the loop holes. 6mm is .236 and 1/4" is .250 if you can't find a metric screw. I suspect there will be some issues.
It is also possible to duplicate what the factory did with another plate, back it up to the one that is there, bolt it down with the footman loop, and then rivet it in place with some 3/16" SS rivets. You could move those out to just past where the door panel opening is cut around the loop and hide them easily.

Saturday I went to Ace Hardware and did some test fitting with the screws. The 1/4" was too big, the 6mm was just about Goldilocks. The holes on the footman loops weren't uniform either, so at least one got a few hand turns on a drill bit to open them.

I saw that O'Reilly's had rivnuts and rivnut installation tools (a 6mm bolt with a larger nut on it), so I gave it a try. It was about $8.00 for the tool and the same for a pack of 6 rivnuts. For the limited use I had of the "tool", it performed great.

If these ever fail, then I'll explore riveting something else in place.

Thanks again, @mrblaine!