Short Arms to Long Arms

[autotragic]

From a suspension geometry standpoint, long arms and track bar position should lead to a better roll center and a better overall feel at high speed. At the end of the day, "travel" is limited by two things: shock length and binding. If a "short arm" doesn't bind, and you keep the same shock length, then nothing should change from short arms to long arms in terms of rockcrawling.

What I wasn't sure of is if I'm just not seeing bind in the driver's seat, and if long arms are providing a substantial improvement at speed on a JL. JL short arm lengths are longer than older Jeeps, and so my thought is that people may be holding something against JL "short arms" from legacy applications.

For example, did you know a factory TJ control arm was 15" and a JL is 23.9"? That means a JL has a 9" longer control arm from the factory. The Metal cloak short arms are 24 5/8 making them almost an inch longer than the factory arms to compensate for lift height (that's why they call them a mid arm).
Funny thing is, TJ "long arms" varied from 16" to 32", so they were all over the place and the average was the length of the JL's short arms! So, you could argue that from a comparative standpoint, a JL has "long arms" compared to a TJ =)

That's why I want to know if there's an ACTUAL benefit. Concrete facts that you couldn't flex as far, or there's a difference in high speed drivability. Funny thing is a bunch of people disagree here and that concerns me. It concerns me because that could mean that you're trying to convince yourself it made a difference because you spent $4000 more on those arms.

This is the kind of critical thinking that can save you money and help you sleep at night. I remember installing 4 inch lifts just to clear 33s back in the TJ days. Now you can just install 33s and drive it. The suspension is the same basic design but the JL ain't no TJ that's for sure.

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[Mr. Curti]

I've been wheeling for 25+ years. But, over the last 10+ years I've always wheeled a JKU on tons, Long Arms etc. I have never gone through the transition from short arms to long arms. I just picked up a used 392 and it has an MC "mid arm" (which is just short arms) lift.
I'm wondering if amyone here went to a short arm lift and later did Long Arms and how much of a difference you REALLY saw in performance on and offroad. Was it dramatic? Was it mild? A good Long Arm upgrade kit with brackets, arms and joints is $3500 meaning it's not a small cost so the value has to be there.
Part of the issue here is mental as I'm accustomed to always buying the "best" and I'm feeling like I have something thats junk.
I will rockcrawl this (just spent a weekend at Wolf Caves for example).
Thoughts?

it’s interesting to see your post/question. Because I had the same question. And I was told by the person who is building my diesel that the JL links, from the factory, are longer than the factory links of the previous models. Likewise, what the previous model’s aftermarket long arm links lengths would be slightly longer than the factory link length of the factory jl links. So with people calling the factory links a short arm, in essence, the factory JL links would be considered a mid arm link length. That being said, the difference in length between the factory JL link length and what is considered to be a JL long arm link length is relatively minimal. Now that is given suspension ride hight being equal. So if someone was going to be increasing the suspension ride hight by a substantial amount, then arm length could play a factor. But thst is only if the length of the arms also increases by a substantial amount. Which the difference in most long arms links is minimal in relation to the factory link length.

So measure the length of the links that are currently on the Jeep and look up the length of the links on your desired long arm kit and see what the difference is. Then take a measuring device of your choice and mark out the difference on a surface of your choice so you can visually see the difference. Then ask yourself if that visual difference is significant. If it is, then go to your Jeep and measure that difference from the front tire forward and from the rear tire backwards (at different vertical points) to see if there are any clearance issues. Then ask your self is the juice worth the squeeze?

 

[Roky]

it’s interesting to see your post/question. Because I had the same question. And I was told by the person who is building my diesel that the JL links, from the factory, are longer than the factory links of the previous models. Likewise, what the previous model’s aftermarket long arm links lengths would be slightly longer than the factory link length of the factory jl links. So with people calling the factory links a short arm, in essence, the factory JL links would be considered a mid arm link length. That being said, the difference in length between the factory JL link length and what is considered to be a JL long arm link length is relatively minimal. Now that is given suspension ride hight being equal. So if someone was going to be increasing the suspension ride hight by a substantial amount, then arm length could play a factor. But thst is only if the length of the arms also increases by a substantial amount. Which the difference in most long arms links is minimal in relation to the factory link length.

So measure the length of the links that are currently on the Jeep and look up the length of the links on your desired long arm kit and see what the difference is. Then take a measuring device of your choice and mark out the difference on a surface of your choice so you can visually see the difference. Then ask yourself if that visual difference is significant. If it is, then go to your Jeep and measure that difference from the front tire forward and from the rear tire backwards (at different vertical points) to see if there are any clearance issues. Then ask your self is the juice worth the squeeze?

Not sure where you’re getting your information from, but I’m running RK long arms and they’re 12” longer than stock, I think MC is an inch or two longer yet, but no where near as much ground clearance….

The angle is significantly better as is the ground clearance the way these bars are made….here’s a rough illustration of before and after…..On my rig, a JLUR, the long arms made a significant difference in on road handling and ease of off-roading…..

Here’s an example of how the axle isn’t pulled back, or pulled forward in the rear…… this cleaned up some rubbing I had on the front driveshaft hitting the exhaust at full droop, and the rear diff skid was contacting the gas tank..also there’s no more rear steer over obstacles……see the white jounce bump…..

I gained 3.5” of ground clearance on the rear shock/control arm bracket as well…I actually never realized how low those brackets were…..

Here’s a shot of underneath….

The 3 link rear, really helped with the ground clearance, and ease of articulation…….

Anyway this is real world experience FWIW, and the juice was well worth the squeeze, lol… YMMV………

 

[zonearc]

RK kit improves ground clearance, but I wasn't a fan of their 3 links geometry on the JK for that kit. The rear would float and steer on high speed turns. We worked with them for months and we eventually removed it.

 

[Roky]

RK kit improves ground clearance, but I wasn't a fan of their 3 links geometry on the JK for that kit. The rear would float and steer on high speed turns. We worked with them for months and we eventually removed it.

Yeah, I haven’t noticed any of that, and I drive it like I stole it on the highway, I’m not bombing through the desert though…….. in this thread you said you have the MC short/mid arm kit installed, and in another thread you said you have MC long arms on, did you install the long arm kit, or is it two different jeeps?

 

[zonearc]

This one has the 3.5" short arms

 

[Jtphoto]

The only time I can see where the long arms will provide advantage will be when coupled with coil overs. The regular JK and JL arms can easily handle even long travel shocks like RockSports.

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