Is it common knowledge that the main tube for the sliders be positioned 'under' the pinch weld on the body instead of just outside of it?
I was reading someones site that said that they do this so when the slider contacts a rock and flexs it will contact the pinch weld and disperse the weight along the entire seam. I really wanted to position the main 2x4 tube about a 1/4'' outside of the weld so they would sit just a little bit higher. What are everyones thoughts on this?

Edit: Oh yeh. When making bolt on sliders, do you bolt them through the Whole frame or just one side by tapping it or using self tapping screws. I would think that you would drill a hole through both walls of the frame as i would assume this would be stronger.

Thanks, Sam.

 

First, you don't even want your slider to come in contact with the pinch weld/body seam. That's the reason for having sliders to begin with.

Mine are centered on the tires, whose plane is outside of the pinch weld. Here's a picture showing the whole rail sits to the outside of the pinch weld. Having them centered on the tires seems logical to me as that is the point where you are most likely going to be coming down on a rock.

I'm sure there are a number of theories on how to design them, but as long as they're strong enough and don't cause body damage, they are the right design.

I'm unable to comment on the bolt-on questions.

 

Darren, I'm surprized you don't know about Roger Browns sliders. They are designed just as Sam said, to spread the load out to the pinchweld so that the frame mount doesn't have to be quite as strong. They are a proven design and are used on many trucks around the country.

Sam, whether you use the pinch weld or not depends on the type of slider and how it's designed. If you don't use the pinch weld, self tapping bolts aren't going to work. There was a recent discussion on various mounting schemes in the main forum, try searching for that.

Remember, no matter how stiff you make your sliders, the frame is ALWAYS going to flex and your sliders will deflect some. If you decide to not use the pinch weld, then you have to allow enough room so that the mounting "legs" do not flex up into the pinchweld.

 

Oh, I've read about them, but it has been some time ago. Like I said, if they can take a beating without allowing body damage, then they're the right design. Obviously, his is a proven design, and I am not one to question it. Something about allowing sliders to hit the body just doesn't sound right to me, though.

 

Oh I see. That's understandable about it not sounding right. I thought the same when I saw how the Jeep grand cherokees make theirs. They basically do the same thing, but the mounting legs are tiny and the slider bolts directly to the pinch weld since they have a unibody frame.

 

Ok. So i think i want mine NOT to contact the body. About how much space would i need to leave between the body and any part of the slider. And is it ok to grind on the pinch weld where my 1 3/'' mounting tubes will come close to it. See i want these to sit up as high as possible. If i could grind the pinch then it would give me another1/2''. Im just talking about grinding in 2 maybe 3 places just enough to clear the top of the 1 3/4'' tube.

 

I'll take another stab since there haven't been any other replies.

The minimum spacing should be 1/4" and the max is 1/2". Mine is at 3/8". More room to flex than 1/4", and more clearance, albeit marginal, than 1/2". So, I feel that is optimal. But, it also depends on how strong they're built to begin with. For example, for all those folks without gussets on theirs (read, Stubbs), I would want a bit more spacing than 3/8, and probably more than 1/2, assuming they're really going to get used. The absolute hardest hit you can give Slee's will deflect them exactly 3/8". "JadeRunner" did it and Schaefer took video to prove it. Quite impressive that it only scraped the paint off the pinch weld. These are the strongest out there, so you can make your decision based on that.

I've seen others trim out there pinch weld, namely "Dozer". It looks a little odd from the side, but it would certainly allow for more clearance as you suggest. They look like castle turrets! There won't be any issues by doing this, though.

 

On a box frame, you'll probably want to drill through both frame walls and then use a sleeve so you don't "collapse" the wall and this will give you maximum strength for a bolt-on. I think Roger's got a write up on this method somewhere on his site.

 

If I were you, I wouldn't drill thru the frame. I'd weld on some stubs that the sliders slip over, one inside the other, then run a bolt thru the tubes where the overlap. Drilling thru the frame is a pain, plus this would be stronger, right guys?

 

You shouldn't get enough frame flex to allow the sliders to deflect much. Don't forget that there's a huge skid plate tying the frame together. The deflection comes from the support legs bending.

 

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Heres an example of my pinch welds cut. I have little over a 1/4 inch space.