Thank you both for your support and ideas.
That welding idea would probably be the cheapest option.
I would prefer not to weld, as that will burn off the factory anti stone chip coating on the surrounding parts of the chassis and inside the cross tube as well, requiring additional rust proofing work to be done.
I would prefer to go with these captive nuts as Lambert calls them (is that a correct name?). Does anyone know if these generic captive nuts can be bought anywhere? I asked Suzuki but they sell only complete side step kits for "$#&#$&" prices.
I am not certain that I completely understand how these nuts are supposed to work.
Please bear with me and confirm if this is correct (I am having difficulties explaining and understanding this as English is not my native language):
- The deep sleeve with side cuts has a constant outer and inner diameter. The outer diameter is about 2 mm larger than the inner one (the difference is actually due to the thickness of the sleeve).
- The minimum diameter of the conical part is a 1 or 2 mm smaller than the inner diameter of the deep sleeve with side cuts.
- The maximum diameter of the conical part is THE SAME as the OUTER diameter of the deep sleeve.
- These two properties enable the conical part to easily slide into the deep sleeve, but only about half way through.
- The maximum diameter of the conical part (and the outer diameter of the deep sleeve) is 1 mm smaller than the inner diameter of the chassis cross tube (so that both of them can easily be inserted inside the tube).
- Now, the whole concept is to somehow "push in" the conical part as much as possible into the deep sleeve while they both are inside the chassis tube. As that happens, the larger end of the conical part will force the deep sleeve to expand (conical's maximum diameter being larger than the inner diameter of the sleeve), thus jamming them both in the chassis tube.
The pushing in should somehow be accomplished by the bolt:
- The conical part is hollow.
- A nut is put through that hole so that the head of the nut is on the bigger side of the conical part.
- Then the bolt is welded to the conical part, so the bolt and the conical part become one part!?
- The deep sleeve with the two side cutouts has a hole in its bottom for the bolt to go through.
- The bolt+cone is inserted into the deep sleeve so that the conical part is partially inserted into the sleeve and that the end of the bolt protrudes through the bottom of the sleeve.
- Now the entire assembly is inserted into the chassis cross tube (bolt head first, then conical part, then deep sleeve), where it has some small slack. The end of the bolt is the only part which sticks out from the chassis tube.
- Now a steel bracket of the side step is put against the end of the chassis tube, so that the bolt protrudes through a designated hole in the bracket.
- Then a washer+nut gets bolted onto the bolt to some strong final torque.
- As the nut is being bolted on more and more, that should force the bolt+conical part to be brought closer to the outside of the chassis tube, i.e. deeper into the deep sleeve.
- This will force the deep sleeve to expand and get jammed into the tube.
There is a risk that the bolt will start to turn as the nut is being turned (there is no way to hold the bolt head while turning the nut). However, that should not happen, because the bolt is welded to the conical part and the conical part is getting jammed more and more strongly into the deep sleeve as the bolting torque starts to increase.
So in the end, the only force which holds that part of the side steps attached to the vehicle is the jamming force of the expanded deep sleeve against the inner walls of the cross chassis tube!?
