mwtrent

My first impressions of everything is really good. The rock rails seem heavy duty and are built up and gusseted on backside. This is a good view of the back side of the rock rails; something I couldn't find on the internet.


I did spot some differences in what I think are probably the welders are their shop. Some have nice thick beads and others look like they could have used a little more metal in the pool. In the end I doubt it will hurt anything especially considering my intended use but I felt it should be shown. These two pics are the same weld location on the passenger side vs the drivers side.


There were some other variances as well. It's a little hard to spot in the pictures but if you look closely at the same rock rail that had the smaller weld beads you will see a dimple that appears to have a hard crease and another small weld. Its big weld counterpart is smooth with no creases in the transition and a much less pronounced dimple.


As of right now, pre-installation, i'm happy with everything and can't wait to get the install started. I'm a little nervous about the rivnut installation but I should be able to manage. I'll start with the rock rails to get the hang of it before I move to the exo-skin. More pics and thoughts to come later. Let me know if you would like to see pics of anything in particular and i'll get it posted.

DallasJKU

The only reason I asked is because I have read numerous threads talking about how the stock bolts ovaled out the stock track bar and lead to death wobble.

14Sport

...due to being improperly torqued.

Invest2m4

Exactly. A 9/16" bolt can oval out a hole as well.

Some people don't use a torque wrench, some use cheap ones or ones that are way out of calibration, and others use poor procedure. Ideally, the torque should be done on the nut, not the boot head. Otherwise, you likely end up with a low torque value.

14Sport

...and rechecked frequently, especially after wheeling.

Invest2m4

A little bolt science, borrowed from another site because I am too lazy to expand on the topic. Point 2 and 3 are most relevant. Fully threaded bolts stretch more and different grades stretch a different amount. Torque is not a 1 to 1 relationship with clamp force. Also, bolts designed by auto manufacturers are designed together with the nut as there are specific tolerances between the two.

If you want more information, a good place to start is the basic tutorial from A Tutorial on the Basics of Bolted Joints. For our purposes we must understand that:

-Technically speaking, SAE (i.e. automotive) fasteners (bolts or studs, and nuts) in a bolted joint are not designed to carry a shear load. They are designed to clamp the 2 parts together, so that the friction between them carries the load - or at least the majority of it. In reality - SAE fasteners do do this but also usually carry some load in shear.

-That in order to carry out their duty as "clamps", they must deform (stretch) a fairly precise amount upon installation / tightening so that the resulting force that tries to return the fastener to its original length achieves the clamping force. The most common and easiest way of approximately measuring this stretch (and thereby being assured that the proper clamping force is achieved) is by measuring the torque with which the fastener is tightened in the assembly, as this has a direct, mathematical relationship to the amount of stretch.

-Fasteners of differing "grades", materials, and construction methods (hardening, tempering etc.) have vastly different strengths, ranging from SA grade 1 bolts with a yield strength of 36,000 psi to SAE grade 8 bolts with a yield strength of 130,000 psi. This directly affects the maximum stretch that they can endure without permanently deforming, and therefore the amount of clamping force they can develop. We see this as different maximum torque values for different bolts. Hopefully , we now see this as not just "how tight do I have to do it up", but rather, "when I tighten this fastener, how much clamping force can I develop"

-And finally, because of fastener preload (explained well in the Bolt Science tutorial) a properly tightened fastener is vastly stronger than a loose sloppy one.

NJKURPat

Why does bolt head vs nut make a difference?

DallasJKU

Some install pics. It will be done sometime tomorrow.

14Sport

Coming along. Did you install all 4" of bump?

DallasJKU

The shop did install all of it and will adjust as necessary.