ROCK HARD 4X4 Front Control arm skids.

[Chocolate Thunder]

Well I thought about it for a while and decided I'm not in a rush. I've helped wrench on a friend's older GX470 with a ton of rust issues. They are a huge pain and I want to avoid that if I can. I also don't want to deal with the deforming washer, and maybe any clunking, loosening, or other issues -- is it that the washer provided was designed with their original torque specs in mind (someone said they first recommended 100 ftlbs), they kept revising the torque up to OEM spec, and didn't change the provided hardware? And then the idea is that after the washer deforms, the skid slowly does too, which then causes the issues?

I suppose I'll just buy everything on the shopping list that was posted by @swang and @Gadgettr1. Just for a clarification, are some of those washers meant for as total replacements for the shims, or just in addition to the shims? And do you think it's preferable to use their shims over the washers on a new install? (and just fill in any gaps with washers?). Just wanna get this right on my first try, and maybe have it all written down nicely for others that follow.

I didn’t replace the thick shims with new washers. There’s not a need, and washers would be more of a PITA to install in that location. The RH shims are tabbed to allow you to hold them in place and adjust their position while lining everything up and inserting the bolt. Perhaps get an extra washer or two so that if there’s play when you’ve assembled everything you could use them if necessary to take up that space. If not, it’ll be difficult to get a good tight fit when torquing the bolts and you could get a clunking noise. I believe this is more a function of loose manufacturing tolerance in the mounting ears by Jeep rather than the RH parts.

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[blink9cd]

I didn’t replace the thick shims with new washers. There’s not a need, and washers would be more of a PITA to install in that location. The RH shims are tabbed to allow you to hold them in place and adjust their position while lining everything up and inserting the bolt. Perhaps get an extra washer or two so that if there’s play when you’ve assembled everything you could use them if necessary to take up that space. If not, it’ll be difficult to get a good tight fit when torquing the bolts and you could get a clunking noise. I believe this is more a function of loose manufacturing tolerance in the mounting ears by Jeep rather than the RH parts.

Ok cool thanks for the guidance and clarification. I just put my order in at Belmetric for the shopping list provided earlier, and added in some extra nuts/washers while I was it to be on the safe side.

Update: Belmetric already shipped, arriving by Fri. That's even faster than I can arrange to do the install.

 

[Gadgettr1]

Well I thought about it for a while and decided I'm not in a rush. I've helped wrench on a friend's older GX470 with a ton of rust issues. They are a huge pain and I want to avoid that if I can. I also don't want to deal with the deforming washer, and maybe any clunking, loosening, or other issues -- is it that the washer provided was designed with their original torque specs in mind (someone said they first recommended 100 ftlbs), they kept revising the torque up to OEM spec, and didn't change the provided hardware? And then the idea is that after the washer deforms, the skid slowly does too, which then causes the issues?

I suppose I'll just buy everything on the shopping list that was posted by @swang and @Gadgettr1. Just for a clarification, are some of those washers meant for as total replacements for the shims, or just in addition to the shims? And do you think it's preferable to use their shims over the washers on a new install? (and just fill in any gaps with washers?). Just wanna get this right on my first try, and maybe have it all written down nicely for others that follow.

Well I've got the clunking noise back in my front end. I'm going to try and get it up on a lift and look at it with a buddy from my local Jeep club next Tues. I replaced the original bent skids and upgraded the hardware with washers (from the previous posted list). Full disclosure I didn't do the install so I can only hope the washer stack was actually done correctly (I'll find out Tues), I had no noise for a while but it's now back. If the skids are bent again I might have to revisit having front lower control arm skids (unless of course it was an install/washer stack error on my installer).

 

[blink9cd]

Yes, sorry, that’s what I was replying to.

It’s really a result of the opposite thought process happening, bigger/stronger hardware is more expensive, so the engineer (with a factor of safety) will target the smaller hardware that can take the required loads and clamping force. The specified torque varies a little even for the same size/grade bolt, but in general the torque spec will follow the size pretty closely.

In the stock suspension:
M10 is 45 to 50 ft lbs
M12 is 60 to 80. (Front UCAs)
M14 is 90 to 120 (Track Bars, rear CAs)
M16 is 190 (Front LCAs)

Ah that's really interesting. Once you pointed that out, now I look at that chart, and yeah, the torque values do follow with the bolt used.

So to repeat to make sure I understand, it seems to me engineers figure out what the clamping force needed is through some process (would like to understand this a bit more, for now will say through some sort of known theory/modeling/testing process). This is what determines the difference between front LCAs and rear LCAs, and why the front are so high compared to the rears. Once establishing that torque value needed, they find bolts where that's at the top of the range, which is why they're different (minimizes the cost).

But then that leads me to wonder how the Rock Hard instructions could ever be right, and that there's no way the rears could ever be 190ft lbs of torque. The reason should be implicit in their instructions they say they provide M14 bolts, just like OEM, which aren't rated to 190 ftlbs (for the reason in previous paragraph). And thus if you followed the explicit instructions you would leave yourself vulnerable to issues with overtorquing like the thread stripping, stretching or breaking the bolt, etc.

I suppose you could say maybe Rock Hard did their own engineering test process to figure out the clamping force needed was changed by the skid (which would be interesting on why a skid would change that?), but then if that was the case, wouldn't they provide an appropriately rated bolt?

 

[Chocolate Thunder]

You are REALLY overthinking this.

 

[Chugiakguy]

You are REALLY overthinking this.

VERY few people nowadays, I would say, are guilty of overthinking!

 

[blink9cd]

You are REALLY overthinking this.

I wasn't quoted but this is right after my longer post, so imagine this is to me, and thus I won't deny it lol. BUT I do wanna say that some of the enjoyment of this from me is not only driving the Jeep, and not only learning HOW to turn the wrenches, but also learning WHY I'm doing what I'm doing. Especially when I know this is a 100% designed endeavor from the beginning where (a lot of) people have spent (a lot more) time thinking about all this.

In particular for this thread, I don't wanna be the guy who buys new hardware because a guy on the internet said so, but because I understand the differences from what I had before and what it will accomplish. I also don't wanna blindly follow instructions that don't seem right or congruous a whole, especially when I know they've changed several times, and that people have been (and are still having) issues. Don't even get me started on the "pieces are not side specific" for pieces that aren't identical...cause you know I wanna ask how that could be too.

So yeah, I'm still in the period where I still need to ask "why" on a lot of this, and it's public due to the nature of the forum. But the good news is, once I understand, I'll not only not have to ask in this specific case again, but it'll compound into a future where I naturally won't even have to ask.

 

[blink9cd]

Well I've got the clunking noise back in my front end. I'm going to try and get it up on a lift and look at it with a buddy from my local Jeep club next Tues. I replaced the original bent skids and upgraded the hardware with washers (from the previous posted list). Full disclosure I didn't do the install so I can only hope the washer stack was actually done correctly (I'll find out Tues), I had no noise for a while but it's now back. If the skids are bent again I might have to revisit having front lower control arm skids (unless of course it was an install/washer stack error on my installer).

Sorry to hear this. I'm jealous you get to use a lift (I've always wanted to try that). There's no chance I'll be able to do an install before then anyway, so I'll appreciate hearing what you figured out. Good luck!

 

[swang]

Wow… I haven’t visited in awhile and this thread has really grown! I still have not installed the skids yet. Like some others, I’m hesitant to do so given the number of issues that seem to keep cropping up. Might try to sell them along with the new hardware (bolts/nuts).

 

[GATORB8]

Wow… I haven’t visited in awhile and this thread has really grown! I still have not installed the skids yet. Like some others, I’m hesitant to do so given the number of issues that seem to keep cropping up. Might try to sell them along with the new hardware (bolts/nuts).

Lol, just do what I did, I'm halfway through a cross country wheeling trip with only the driver side skid installed.

 

[conFUcius]

I purchased the bolts from Belmetric.com. I'm sure I could have gotten them cheaper somewhere else, but it was convenient and I received them in a few days. I understand the Rock Hard brackets are a little too wide and torquing to 190 ft-lb is bending them. I wanted to buy a washer to fill the gap but I didn't know how thick the washer needs to be.

Did you end up TQ-ing these to 190 as well?

 

[davewald]

An update on my experience. I had them on both the front and rear, and experienced clunking from both from the start, regardless of how much I cranked them down (air impact, jack under the wrench, etc.). I had the rears spot welded on, but thought I could manage to keep the fronts from loosening up. Nope, and no easy way to spot weld them like the rears. After the Rubicon Trail and now Moab, I have finally given up on the fronts and took them off. They are great at skidding over rocks, but suck at staying tight enough to not clunk. I bought a set of weld on skids for the front, and no more clunk. They don't cover as much as the RH bolt on's, but THEY DON"T CLUNK. RH needs to figure out a way to make great bolt on skids that don't keep loosening up.

 

[blink9cd]

An update on my experience. I had them on both the front and rear, and experienced clunking from both from the start, regardless of how much I cranked them down (air impact, jack under the wrench, etc.). I had the rears spot welded on, but thought I could manage to keep the fronts from loosening up. Nope, and no easy way to spot weld them like the rears. After the Rubicon Trail and now Moab, I have finally given up on the fronts and took them off. They are great at skidding over rocks, but suck at staying tight enough to not clunk. I bought a set of weld on skids for the front, and no more clunk. They don't cover as much as the RH bolt on's, but THEY DON"T CLUNK. RH needs to figure out a way to make great bolt on skids that don't keep loosening up.

Sad to hear about the clunking on both front and rear. I haven't read through this thread in a long time, was clunking on the rear common? If I recall it was on the front...I haven't actually tried installing mine yet. There were other Jeep and life projects that moved forward in the queue, either for being easier to install or more immediately useful (and in fact I still have one or two I'd rather do first...).

 

[davewald]

Sad to hear about the clunking on both frunk and rear? I haven't read through this thread in a long time, was clunking on the rear common? If I recall it was on the front...I haven't actually tried installing mine yet. There were other Jeep and life projects that moved forward in the queue, either for being easier to install or more immediately useful (and in fact I still have one or two I'd rather do first...).

Yeah, the rear clunk was solved by the tack welds. No way to do that on the fronts, and frankly I don’t think it would have solved the problem anyway. RH needs to redesign.

 

[JMP]

I’m using RH on the front axle and frame sides, Rusty’s rear frame, and Artec rear axle. As of now, with all torques correct, no clunking. Fingers crossed.

I kinda liked getting the bare metal Rusty’s… get them powder coated red

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