Round, Round, Get Around, I Get Around…

Before I get into this week’s tale, I want to correct the wheelbase numbers I posted last week. I should have caught the error at the time, but I didn’t. It turns out that the “inner” wheelbase is still about 98 inches (up from 81 on the CJ-5), but the “outer” wheelbase is actually around 138 inches, instead of the 130 I told you about last week. The reason I say I should have caught it is that I know the two back axles have to be about 40 inches apart, center to center, in order to clear 35-inch tires with a reasonable amount of space between them. So the outer wheelbase on the JeepMonster will be about the same as my truck’s. The shorter overall length (16 feet for the JeepMonster versus 18′ 8″ for the truck) is due to the lack of front and rear overhangs.

So, having cleared up that little tidbit, I’ll move along to this week’s visit with Robert – and the things that I had to get done before going.

It turned out that the stock JK Wrangler coil springs I had taken to him were about the right stiffness, but they were too long and too wide. So my assignment was to find something a couple of inches shorter (16 inches instead of 18), an inch less in diameter (four inches instead of five), and with flat ends instead of the square-cut coil ends that come from the factory. And oh yeah, I could also get some shock absorbers, too – Robert’s keeping his set for his own project. He gave me the brand name, the series number, and the SKU for the shocks he was using, and since I had all that, I decided to make life easy on myself and just get more of the same.

I looked online to find them, and discovered that 4 Wheel Parts had exactly what I wanted. I decided to go to the store to get them, on the theory that doing it that way meant that at least *some* of my money would stay here in town. Naturally, the store didn’t have any – they were on backorder and wouldn’t be in for a few days. Okay.

Next I asked the man behind the curtain – er, counter – if he had any recommendations or suggestions on how to find out how stiff the JK Wrangler springs were. Coil springs are rated in “pounds per inch,” which means that for a set weight (100 pounds, 200, 400, etc) the spring will compress one inch. I needed the JK’s spring rating so I’d know how stiff the new springs would have to be.

The 4 Wheel Parts counterman suggested I go see someone named Brian at someplace called ADS. Luckily, Mapquest (mobile) was able to find ADS Racing Shocks for me and off I went. I met Brian, and he was happy to show me what they had (they build coilovers, so they have lots of different springs on hand – all of which have flat ends and a four-inch outside diameter). Unfortunately, he couldn’t help me with determining the JK’s spring rate, but he knew a man named Paul at GAT Racing (Brian called it a “roundy-round” shop – GAT builds circle-track race cars) who might be able to help.

So, off I went to GAT, again with help from Mapquest. Paul was there when I arrived, and he knew exactly what I wanted (thank goodness!), so he took my spring back to the back and invited me to come along. He clamped the spring into a small hydraulic press and pumped the press until the entire spring was just slightly compressed. Then he zeroed out the force indicator and compressed the spring one more inch. When he was done, the indicator read 126, meaning that the spring was probably a 125-pound unit. This surprised me, because JK Wranglers can weigh over 1200 pounds per corner, but okay – that’s what the spring machine said.

Back at ADS, Brian went looking for comparable springs and came up empty-handed. In a 16-inch length, he had 100-lb springs and 400-lb springs, with nothing in between. Oh yes – he had *one* (used) 200-lb spring. So I bought a pair of the 100-lb springs and the 200-lb spring. I figured that Robert would be able to use one or more of them to at least begin fitting the spring mounts, even though the springs themselves were the wrong stiffness. I told Brian what I was doing, and he was okay with my plan to exchange the 100-lb springs for a pair with the proper stiffness, once we figured out what that might be (and as long as we don’t scratch the ones I bought).

I took the three springs, and a bunch of other pieces-parts, to Robert this past Wednesday. [The shocks arrived at 4 Wheel Parts on Wednesday morning, so I was able to take them to Robert, too.] As a test, we placed the 100-lb springs between the frame and the front axle and then let the frame compress the springs. They flattened out almost exactly four inches (from 16 down to 12-ish) before they fully supported the front end. From that we concluded that the front of the frame, with the engine and all, weighs about 800 lbs, equally supported by the two springs. That number will go up, of course, as we add the winch, and the body, and the fluids, and whatever else goes on the front.

We also checked out a couple of other things and then I came home. [I took some pictures of the transmission mount in the hope that either Advance Adapters or Novak Enterprises might be able to help me with a replacement.] On my way out, I took a couple of pictures of the forlorn remains of the CJ-5:

DSC00109

DSC00110

So for my next visit, I’m supposed to have (if I can get them in time) the correct-strength coil springs, the new radiator, the right-length U-bolts for the back axles, and some information on the clutch slave cylinder I’ll be using (so Robert will know how to route other things around it).

Stay tuned.

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Categories: 6x6, CJ-5, JeepMonster, suspension | Tags: , , , , | 2 Comments

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2 thoughts on “Round, Round, Get Around, I Get Around…

  1. Miles W

    learned more about springs here than I ever wanted to know. God Bless your patience & dedication to this project.

  2. It is coming along, though.. and quite nicely! 🙂

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