Removing the dreaded 10 mm nut/bolt (Mk2 rear bumper)

[koffertfisk]

Hi everyone,

I'm currently stuck trying to remove the rear bumper of my Ford Focus Mk2 (2009, estate) and could really use some advice. The problematic part is the dreaded 10 mm nut and bolt behind the wheel arch. As you know, the bolt head is in a position that's nearly impossible to reach.

Here's a breakdown of the situation:

Close-up photo: Shows the washer, nut, and threaded pin. The bolt head isn't visible because of its awkward placement.
Wider angle photo: Displays the relationship between the two bumper pieces and the problematic nut.
Rivet heads photo: Taken from underneath the bumper, showing the rivet heads.
Rivet tails photo: Illustrates the tails of the rivets.

I suspect the only viable solution might be to drill out the two rivets, but I'm hoping to avoid that if possible. Any tips or tools you would recommend for getting this nut and bolt off without causing damage?

Thanks in advance for your help!

 

Best Regards,

Marcus

[troy45]

Is it not simply a case of the 6mm stud being captive to the bumper and you just need to undo the M6 nut?

Might need the exposed thread tidying up to help but you’ve got to bear in mind that the bumper would be fitted in the factory with the various plastic reinforcements already in place and would need access to do up all the fixings. Would be very surprised if there is a bolt used there, lot more likely a captive stud?

One way to help clean up the stud for the nut to come off would be to run another nut down it maybe half a turn then backing off a bit at a time 

[DaveT70]

I'd have to agree with Troy.

Clean the threads and fit two nuts on the end of that thread and tighten them together.

Then hold the nuts, to stop the thread from breaking it's position and spinning and undo the main nut

[troy45]

1 hour ago, DaveT70 said:

I'd have to agree with Troy.

Clean the threads and fit two nuts on the end of that thread and tighten them together.

Then hold the nuts, to stop the thread from breaking it's position and spinning and undo the main nut

Absolutely this - looking at some YouTube videos the other end of the ‘bolt’ is actually square. This ties up with it being a captive stud. May spin in its recess etc if the nut is tight on the threads which following Dave’s advice above will help you to avoid 

[koffertfisk]

Thank you all for your input. I've been too occupied with work for the last few days, but I found some time today to continue working on this. The idea of fitting two additional nuts in order to undo the main nut is brilliant. However, cleaning the threads proved to be more challenging than anticipated... There's still a long way to go, as you can see in the attached photo; I'm nowhere near being able to thread another nut on it due to the remaining rust. I'm using a steel wire brush and a pick tool for this. I guess that's the way to go?

[mjt]

A Dremel with small rotary wire brush would be quicker.

[unofix]

You could just run an M10 die nut down the stud which will clean it and re-thread it at the same time.

Just be careful that you use the correct thread pitch, there is an M10x1.5mm and an M10x1.25mm

[troy45]

A die is an option or get some oil on it and gradually run a nut down the thread to clean it up. 
 

Small correction to the above post, it’s a 10mm spanner for the nut but will be a standard M6 thread (M6x1.0 me thinks)

An M10 die may struggle to touch the stud 🫣

[unofix]

4 hours ago, troy45 said:

it’s a 10mm spanner for the nut but will be a standard M6 thread

You are indeed correct 👍

[koffertfisk]

So I was able to clean the threads as close to the nut as I could. I then fitted two additional nuts and tried to spin the bolt while holding the inner nut in order to unscrew it. Unfortunately, it was way too stuck and tricky to hold onto, so it is now rounded. I guess the only option from here is to try and split the nut?

[troy45]

Try a small pair of mole grips on it if you’ve got some?

[DaveT70]

should've put the correct fitting ring spanner on the main nut, before putting the two nuts on