I tried to search for this, but didn't really get any wiser...
Where do you guys attach your shackles etc when doing recovery?
For rear I thought about fabbing a couple of these attached "pulling points" to bolt to the four holes / side holes marked with arrows. Any opinions?
I haven't done any calculations yet, but I thought about using 20-25mm steel since I have a lot of that around.
What about the front? The front hitch looks like an obvious choice to me.
How big shackles would you recommend for a approx. 7000kg camper? How about 25t EN 13889 shackles? Is this overkill? Too little?
From the BillaVista's Recovery Bible I read that a truck stuck up to it's chassis gives 3x loaded weight resistance. If my truck is 7t I'd be looking at 21t force in the "worst case", right? I thought about using this as my general rule when dimensioning stuff so that the weakest link can take at least 21 000 kg.
If you have the "knuckles" just go to them. They will take a shackle through the holes. I'm assuming you don't have them, or you would not be designing something that goes in their place.
If you don't have them, make sure the support structure inside the rear cross-member is there. That piece is what gives those mounts the strength for the load, as it ties the rear of the frame together. It is the LIME-GREEN piece in the colored diagram.
On some trucks, it seems that the knuckles just bolt to the rear crossmember, but on mine, they bolt through the cross-member and then through a cast bracket that ties the cross-member to the frame rails, which has to be the stronger arrangement.
Sorry I forgot to mention that the pic I attached is not from my truck and I don't have a rear hitch (anymore, I sold it).
That photo shows the 4 bolts holding the Ringfeder to the brackets.Those brackets are what I have a recovery pin and lynch pin through, and all my heaviest recovery work hase been loaded through that bracket, to mo ill effect.