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WHAT IS IT?: The 2020+ F54 Clubman JCW, BMW F40 M135iX, and BMW F44 Gran Coupé M235iX (and maybe a couple other models ?) have added bracing on the front subframe. See the Red Arrows below. We'll add those to cars that didn't come with them, like my 2017 Clubman S ALL4.
From the hardware store. We need to make a tool to install/expand the blind rivet nuts. Check the YouTube video linked below if you’re unfamiliar with these.
• Class 10.9 or 12.9 M10 bolts. Lower grades aren't strong enough!! They need to be 1.5/Coarse threads, fully threaded and at least 50mm long. I found 50mm ones at Advance Auto. McMaster Carr is another option.
• Class 10 (or stronger) M10 / 1.5 coarse nuts.
• Class 10.9 (or stronger) washers.
You can maybe get by making just one tool, but crushing the blind rivet nut takes so much force that you might damage even a 10.9/12.9 Class bolt. I’d suggest getting four bolt/nut/washer sets, one for each rivet nut.
• IF YOU NEED TO DRILL YOUR OWN OUTER MOUNT HOLES: A short M10 flange head bolt with a 13mm wrench head. We will use this to scratch a hex-shaped outline for the hex shaped blind rivet nut.
WHAT TOOLS DO I NEED?:
• 13mm socket / wrench for the factory bolts.
• Wrenches for the Rivet Nut tool you're making. They will vary depending on what nuts/bolt you find.
IF YOU HAVE AN OLDER VEHICLE LIKE MY 2017:
• 3/8" or 10mm drill bit
• A quality metal file that's 1/4" (6mm) wide MAX. I used a Craftsman CMHT22312 "Extra Slim" taper file.
WHY A DRILL BIT AND FILE?
The best I can tell, all of these subframes have unused provisions from the factory to install the Genuine MINI Blind Rivet Nuts at the inner mounting points. The subframes have hexagonal holes punched in the subframes to accept the hexagonal blind rivet nuts. It appears later build cars also have the unused hexagonal holes from the factory at the outer mounting points. My 2017 Clubman does NOT have the holes at the outer mounts, so I needed to make my own. If you have factory hex holes in both inner and outer locations, this will be super easy.
HOW TO:
1). Install the blind rivet nuts into the inner mounting points first. If you need to drill the outer points like me, doing this will help you locate the drill points for the outer mounts. We will use the braces themselves as a template on where to drill.
If you've never installed one before, this video will do a better job that I can describe. Watch it first! (it’s not my video)
Here's what my tool looked like before I installed the rivet nut. I'm not sure if the video mentioned it, but I highly suggest greasing the threads on your installation tool where the nut and washer are.
And here's installing the inner nutserts with an older version of my nutsert installation tool. If you already have hex holes at the outer points, install those too and you're pretty much done! This old tool I used was NOT 10.9/12.9 class and it destroyed the threads on the tool.
The rest of you need to drill a 3/8" or 10mm hole and then use a 1/4" wide file to make that round hole a hexagon. Next, install the braces using the factory bolt and the inner nutserts you just installed. The braces have arrows on them that point forward. With the braces mounted and used as a template, you can get a good idea of where you'll need to drill for the outer holes.
I searched Euro eBay listings for these subframes to find clear photos of where the factory holes are. That and playing with a partially installed brace, you should be able to come up with a good spot to drill. There's definitely some slop involved, so it doesn't need to be laser-perfect! I found my spot, used a center-punch to dimple the steel, a small drill bit to drill a pilot hole, then finally a good 3/8" bit to drill the final hole. I double checked my marked location after every step with the factory brace to make sure it still lined up.
Heres a low res example of a subframe with factory outer hex holes.
FACTORY OUTER HEX HOLES
Here's mine after drilling my 3/8" holes. Theres some silver sharpie around my hole making it look messed up, but it's not actually.
Now we'll grind off the flange on the M10 flanged-head bolt that uses a 13mm wrench. The MINI rivet nut is a 13mm hex too, so this bolt head outline will match the rivet nut.
Ground-off flange bolt
Insert bolt in 3/8" / 10mm hole and use a awl or other sharp tool to mark the outline of the 13mm bolt head.
Hex marked
Now take your little 1/4" file and get working on taking away metal to match the hex outline. Use one of the rivet nuts to keep checking you work until it fits inside perfectly.
Freshly filed
We don't want this to rust, so take the time to debur, clean, prime and paint the hole. I also used Cosmoline anti-corrosion spray after the paint had dried and while installing the rivet nuts at this location. Here's mine immediately after the last coat of paint.
Once the paint is dry, install the outer rivet nuts. The right (possibly left, I forget ) side brace does directly cover up one of the felt underbody retainer screws, so I didn't install that one screw. The braces have foam rubber pieces that help hold up the underbody tray in that spot anyway.
Outer nutsert installed and sprayed with Cosmoline.
All done!
It does seem a bit odd to have a brace here because it just connects the subframe to itself, and the steel is beefy and round, so you wouldn’t think there’d be much flex here. But I guess since the factory designed it, it must do something 🤷🏼♂️
I haven’t driven it yet. Will report back later.
This mod will be used on conjunction with the factory MINI strut tower brace used on the same cars. DIY coming later on that!
Last edited by AutoCoarsen; May 17, 2020 at 06:04 PM.
