EVO 1/4LB question

[DWiggles]

So why are the okay for the d ring mounts?

The units for loads are all in pressure (force over distrubuted area) so the reason socket cap screws provide acceotable mounting for the d-ring mounts is because the relatively large contact area of the d ring mount to the bumper in comparison to the distance from the plate to the shackle. when you apply a load to the stinger (or example hang on it) you are now MUCH further from the *relitively small* contact area of the stinger mount to the bumper in comparison to the hoop of the stinger.

Edit: force over area, multiplied by distance is a direct multiplier, this is why it is ease to break bolts loose with longer wrenches, this is because you can use a longer wrench, and apply less force to the end of the wrench and through the simple "moment mechanics" you can apply a LOT more force on the stubborn bolt. This is the same concept described above ^^^

 

[olram30]

Nobody's evo bumper has fallen off that I know of. I think the allen bolts are fine.

 

[DWiggles]

So should the Allen head bolts for the bumper be replaced? Mine has them holding on d ring mounts

Not at all, I'm sure the math was done, these parts are designed by an engineer at EVO Manufacturing. I'm sure they have designed it with a ASME/SAE standard safety factor of 2.5 minimum. (2.5 times the DESIGNED expected force limit) it's hard to tell what these limits are without talking to the people directly involved with the design constraints when the bumper was originally a sketch on a piece of paper.

 

[HighwayTrout]

While D wig is mostly correct on all his posts. The smoking gun here is torque, clamping force and of course use of said bolts.

While he is correct that those fasteners may shear at a lower threshold compared to other bolts.
If used properly they are as safe as any other bolts of the same grade.

Here is a sheared cap bolt. Sheared due to improper use and torque. .

I didn't hesitate to reuse another cap bolt in that steer arm once I fixed the problem that caused it to shear.


Anyway all my rambling above could be summed up like this.

If your scared of cap bolts. Don't look at what's holding on your brake calipers.(GM, ford, not your JK)

 

[JKbrick]

Nobody's evo bumper has fallen off that I know of. I think the allen bolts are fine.

That's what I was getting at, why would EVO sent inferior bolts when everything I have purchased from them has been so nice

 

[DWiggles]

While D wig is mostly correct on all his posts. The smoking gun here is torque, clamping force and of course use of said bolts.

Exactly, we are saying the same thing just using different words.

Clamping force is the resultant a function consisting of variables including tightening torque, along with thread pitch, and friction, but for all intestine purposes, tightening torque is the only "input". However, clamping force is ultimately limited mechanically by either the hardness of the fastening surface (I.E. the hardness around the inner surface of the socket cap screw, or the hex head of a stardard bolt) or the tensile strength of the bolt itself, depending on which is compromised first. A sheared bolt is the result of surpassing the tensile strength of a bolt, while a stripped bolt is a result of requiring a higher surface hardness to transfer the torsional load without causing deformation of the material past it's elastic limit...

 

[olram30]

My head hurts now.

 

[Christarp]

Roger that! If so I was going to say make sure you have a good drill bit to drill the holes. the bumper is a piece of cake - just heavy. You just need a good cutting device to cut the crash bar, if you are using a sawzall I would recommend getting some long new blades.

+1 on the good drill bit..... if you get the stinger of course.

 

[chipper]

Thinking of getting one of these. But I'll have to wait on a stinger. And a winch. Does anyone think it would look good installed without them?

 

[JKbrick]

Thinking of getting one of these. But I'll have to wait on a stinger. And a winch. Does anyone think it would look good installed without them?

In the same position, I think it looks fine but that's just my opinion

 

[chipper]

I was just looking at Northridge about this bumper. It states that it does not fit with warn zeon winch. Is this true?

 

[olram30]

Thinking of getting one of these. But I'll have to wait on a stinger. And a winch. Does anyone think it would look good installed without them?

That's how a had mine until I saved up for the stinger and winch. I didn't mind, anything was better than the factory bumper.

 

[olram30]

I was just looking at Northridge about this bumper. It states that it does not fit with warn zeon winch. Is this true?

I think they have a newer design that lets you mount one. I have the older style

 

[chipper]

I think they have a newer design that lets you mount one. I have the older style

I found one for $200 no stinger tho. But I know I want a zeon and didn't want to waste my time if it won't fit. I'm sure it's a older style. What do you think?

 

[olram30]

I found one for $200 no stinger tho. But I know I want a zeon and didn't want to waste my time if it won't fit. I'm sure it's a older style. What do you think?

Look at the holes underneath. I think the newer ones have extra mounting holes.
Actually I'm really liking the new pro bumper. I would really have fine with that if they were available when I got mine.

 

[chipper]

Yup me too on the pro. Plus it will fit the zeon and power plant. I think i like the smaller stinger too. Well I think I made my mind up. That's a great deal for $200 used too. Oh well.

 

[A_R_A_W_N]

What did everyone do with your wires for the fog lights?

 

[OverlanderJK]

What did everyone do with your wires for the fog lights?

Cut them or zip tie them out of the way.

 

[A_R_A_W_N]

Thanks trying to figure out the evap now, i have it un installed and trying to figure out how its supposed to mount

 

[Panda]

Thanks trying to figure out the evap now, i have it un installed and trying to figure out how its supposed to mount

It goes back very close to the sway bar, relocation bracket and shims go between the sway bar mounts and frame