Axle Swap

I finally got all my ducks in a row yesterday: Both back axles were in hand, I had spring perches (to make things more interesting, one axle is built with 3-inch tubing and one with 3 1/4-inch tubing, so I had to get perches that were axle-specific), the welder was available (it had been here at the house for a while, but I eventually got it to the JeepHouse), *and* I had some available time!

So I traipsed over to the JeepHouse and got to work. I started with the axles bass-ackwards from where they belong, in that the “Magic Box” was on the rearmost one, and the simple pinion was on the middle one:

Obviously, the first step was to remove both from the ‘Monster:

You can see here that the perches on the nearer axle are closer together than the ones on the farther one. That’s because the springs for these axles overlap in between them. (You might be able to see the overlap in the first photo, if you look closely.) My plan was to add a new pair of perches on each axle to fit the other springs.

Here you see both axles after I tacked on the new perches. I got lucky: When I was planning all this out, I honestly didn’t know whether there would be space on the nearer axle for the inner passenger-side perch. As it turned out, there is – barely. The inner U-bolt *just* fits around the axle without touching the third-member housing. (My hat’s off to Robert Wonsey, of R&W, who told me from the start that swapping the axles would work and everything would fit.)

Once the perches were ready, then all I had to do was put the axles back under the ‘Monster. It wasn’t as easy as getting them out, but without too much more trouble I got them back in – this time in their correct locations!

I was even smart enough to check for clearances with the center axle springs fully compressed. I had been worried all during the build that the “Magic Box” might be too tall, and that it would hit the tub at maximum stuff, or that the driveshaft might hit a frame crossmember, or some other disaster might rear its ugly head and throw everything into chaos. But they don’t! At full stuff, without any bumpstops to cushion the impact (e.g., metal frame touching metal axle), the Magic Box misses the tub, and the highest point of the input yoke is a half inch below the lowest point of the frame crossmember. *WHEW*

This photo shows the top of the driver side spring plate making contact with the bumpstop mount. The passenger side was similarly compressed, and NOTHING HIT.

So the JeepMonster is back on its own six tires, this time with all three axles in their correct locations. I’m now working on mounting the engine accessories – power steering, alternator, air conditioning, and compressed air. I have also ordered a new steering column, and when that arrives I’ll start figuring out where it’ll hang in the cab, where it goes through the firewall, and so on. I also need to start looking at clutch, gas, and brake pedal placement. Also fuel, electric, exhaust, brakes…

Wizardry

I haven’t had a chance to visit Robert (R&W Custom Sliders & Offroad) this week, but he sent me some pictures of the progress he’s made on the front axle’s suspension. As far as I’m concerned, the man is a wizard. While it’s true that he has access to some awesome machines, he has to know how to use them to produce what he wants. I could probably learn to cut flat pieces, but his ability to work in three dimensions, and to know how all the flat pieces will go together to make a 3D assembly, are amazing.

First up, we have a photo of two coil-spring perches. While this is upside down (the curves you see at the top will fit around, and be welded to, the axle tube), you can see how a basic 3D shape can be made from flat pieces.

Next we have the truss on the front axle. This is where the top two links (of four) will attach to the axle. You can see the curve on the right side where the new truss meets the axle tube, and on the left you can see that the top plate has a little tab on the near left corner to fit the differential housing accurately.

This photo, from the back of the axle, shows how the plate had to be cut to fit around the differential housing.

The next photo shows a lot of progress after the previous one. The spring perches, which also hold the lower links (and, eventually, the shock absorbers), have been added. The bracket to hold the upper links has been placed, but isn’t yet welded to the truss. The frame ends of the links are held in place so Robert can start designing and fabricating the brackets.

Here’s a view of the axle end of the upper links. A lot of times the two upper links will be mounted to the axle independently, but sometimes (as is done here) they’re combined into one connection at the axle. I don’t know whether one way is inherently better than the other or not, but in this case it made life simpler at the axle end.

The final view for tonight is a shot from the side. All this stuff, when it’s finished, will locate the front axle under the JeepMonster. Springs and shocks, of course, provide the cushy ride <wink wink>, and a GM 350 provides the go power.

In other news, I learned that the right springs will be available from ADS on the 16th. I also finally found some acceptable U-bolts for the back axles; those have been ordered and are on their way. The clutch slave cylinder (that actually pushes the clutch lever when you push the pedal down) also arrived, so that can be bolted in to test for clearance issues.

I’m still looking for a new transmission mount. I’ve had my transmission / transfer case combination for 20 years, and the existing mount has reached its expiration date. However, that exact mount is apparently no longer made – I guess it was an early version of what they use today, but what they use today doesn’t fit. Nothing fits. There are three possibilities that might be usable; I’ll order them to see what Robert can do with them. The ones that aren’t used will be returned.

I’m also still looking for a new radiator. I think my old one was custom-made, but I don’t want to go that route again if I can help it, because even radiators in *standard* sizes are hideously expensive. But I have to make a decision soon, and order something, so that Robert can add that to the frame.

I also need to get the air tanks for the onboard air system. They aren’t a critical fitment issue, but if I get them now, Robert can add the mounting brackets to the frame before we start working on the body. It’ll be one more thing done at the (relatively) easy stage of construction.

Capitulation

No, I’m not giving up on my project – I have way too much money sunk into it to do *that*. But I’m going to have to drag the Jeep over to the frame guy’s shop in order to get the new frame built. Apparently it’s not as simple as welding a rectangle together and then making changes as we go.

As I wrote in my last post, I made an appointment with the frame guy to come over and take a look at some points of interference that I found while mocking up the location of the new front axle. To prepare a little bit better for him, I spent some time Monday seeing how things would fit (or not) in a more real-world situation, with one tire stuffed up into the fender (as if it were on a rock), the other hanging down (on the ground), and the tires turned all the way to one side. (I also took out the radiator so the axle-to-whatever clearances could be seen more easily.)

First, I checked the tire/frame clearances with everything level:

As I had originally figured, with an axle that’s five inches wider on each side than the original, I didn’t have any problem between the tires and the frame. Then I went to the next step, which was to see how well the tires missed the fenders if the Jeep was sitting right on the axle and I turned the tires:

There was a very minor bit of rubbing here, but since the plan is to cut the fenders back and make them flat, I’m not worried about it. Step three was to look at everything with one side squished up and the other dropped down. That took some doing, just to get everything in the (more or less) right place. I physically tied the driver-side of the axle and frame together with some rope and then lifted the Jeep with my handy-dandy engine hoist. As the assembly went up, the axle tried to rotate – forward, backward, it didn’t matter, but the pinion did *not* want to stay horizontal. So I ended up putting a floor jack under the tie rod to keep it from rotating that way, and my hydraulic jack under the pinion itself to keep it from rotating *that* way. And, of course, every time I lifted things a little higher, the jacks had to be repositioned. It was very time-consuming.

But I finally got everything into a good enough approximation of where I wanted it. Then came the fun of trying to turn the tires left or right to see how the interference worked out. One thing I hadn’t planned on was the passenger side of the axle dropping down as the driver side was lifted up (it was pivoting on the floor jack I had used when I was testing the level steering). Naturally, the passenger-side tire hit the floor and the axle eventually lifted off the jack that had been holding that side. So every time I tried to turn the wheels, the dropped one wanted to roll on the floor. I finally worked it all out, though. Ultimately, as far as the tires are concerned, there won’t be any issues with them hitting anything they shouldn’t.

The axle itself, and the steering parts, are a different story, though, and this was what I wanted the frame guy to look at.

We had agreed that he would be here at 9 yesterday morning; at 8 I got a text: “I’m here.” Oh. Okay. I opened the garage door and, yup, there he was. It turned out that he had misjudged the traffic between his shop and my house (it’s 53 miles), and he had made much better time than he had expected to. No problem.

We spent the next 2 hours talking about what I wanted, what he could do, how pieces would fit together, and all like that. One area I still don’t think we see eye-to-eye on is how flexible (fluid might be a better word) most of the build still is. He’s still thinking that a lot of stuff will be in the same relative positions in the “new” Jeep as they are now – like body-to-frame attachment points, the exhaust system, the rear axle (which will become the center axle), and so on. I’ve been telling him that it’s possible *none* of that stuff will be the same, which is why I need a first iteration built instead of a whole frame. I think (I *hope*) we’ll get on the same page eventually.

But anyway, after two hours, he finally convinced me that he’d be able to make progress a lot faster if he had the Jeep at his shop, so he could refer to it while he builds the new frame. He also wants the CJ-6 body tub, because it has the same attachment points as my CJ-5, and he’ll be able to measure the -6 for where to put the body mounts on the new frame. I *did* tell him that I’m likely going to replace the floor panels in the body, and put new bracing under them, and that the body mounts didn’t *necessarily* have to be in the same place as they are now. We’ll see how *that* goes.

I foresee many trips to his shop as the frame progresses. I don’t know if he’ll be able to build it all in one pass or not; I think there are just too many things we (I) don’t know right now about running-gear placement, suspension options, body modifications, and so on to be able to do it all at the same time. We did agree, though, that he probably has enough information to build at least the front part of the frame – from the front bumper back at least to the first body mounts.

So that’s where it sits right now. I have to get every non-essential part off the existing frame (things like the fuel-tank switch and the custom battery-jumper cables I routed from the battery to the back of the Jeep) and unload all the miscellaneous junk that’s accumulated in the past 9-plus years, and then figure out some way to safely get it out of the garage and onto a trailer to haul over to his shop. And I have to get all the accumulated stuff out of the CJ-6 body and get *that* over there, too. [The upside of getting the Jeep and the CJ-6 out is that I’ll have space to put the rest of my stuff while I repaint the garage!]

Interference!

Too many things want to be in the same space under the Jeep.

The tie rod and drag link for the new front axle arrived a while back, and yesterday I attached them so that the two tires would stay pointed in the same direction. Today, my friend Tony and I took the old front axle out from under the Jeep and rolled the new one in. Rolling the old one out was actually pretty simple, once the Jeep was on jackstands and the weight was off the axle: disconnect the vent hose, two brake lines, the old drag link (the rod that goes from the axle to the steering box), and four bolts on the springs, then pop the springs loose from their mounts on the frame, and voila! The free-rolling assembly you see here:

Once the old stuff was out of the way, it was an easy thing to roll the new axle into place, although it took us a couple of tries to get it properly centered:

The plan was to get it located right-left and front-back, and then do a bunch of measuring to see whether (or where) things would hit each other.  I wanted to check the axle at “full stuff” (meaning with the Jeep sitting directly on the axle), and also with one end of the axle “stuffed” and the other “drooped” (down at the bottom of its up-and-down travel range), particularly with the wheels turned, to see whether the tires would hit the fenders, the frame, or anything else. I never got to the second part.

What I discovered was that the drag link already sits up very high and farther back than the old one. This means that I’m going to have to relocate the power steering box and get a new Pitman arm (that’s the actual pivoting arm that moves the drag link when you turn your steering wheel). Here’s where they don’t *quite* match up. The drag link is the rod entering from the left foreground and ending in a black-and-silver piece; the Pitman arm is the greyish-white entering from the right center of the photo at a down angle and then turning to point at the drag link. They’re supposed to fit together.

So that all needs to be sorted out.

Then, when I lowered the Jeep down so it would be sitting on the axle, I discovered that the drag link *just barely* misses the bottom of the frame, and the differential wants to share space with the engine’s oil pan:

The differential slid past the oil pan, as shown in the photo, but that’s only because it’s rotated away from its correct alignment. If all those nuts you see were vertical, like they should be, the top of the differential would hit the oil pan big time. I don’t think this will end up being a major problem, though, because I already knew that I’d have to move the engine back to fit the new radiator in. I think I can also move it up a couple of inches, as the new frame will be five inches tall from end to end, instead of varying from 3.5 inches (at the front end) to 3 inches (directly under the grill) to 4.5 inches (at the engine mounts) to 4 inches (under the body) and so on. And I can put in different bumpstops (the red thing in the center left of the second picture up) that will keep the axle from getting so close to the frame in the first place.

So I decided the next thing to do would be to get the radiator out of the way so I could see what hits what (and where) more clearly. Accordingly, I’m letting the coolant drain overnight and will take it out tomorrow.

And my frame guy contacted me on Facebook tonight to see how it’s going. We had a short discussion, at the end of which he said he’ll be here Tuesday morning at 9 (per my request) to have a look and make suggestions. One of his comments was, “maybe we should get started on the frame. that may change some of the issues.” Gee, ya think? 😉

One good point, though – even with the Jeep sitting directly on the axle, the front tires didn’t hit the fenders at all. So I’ll have plenty of vertical clearance between the two when I trim the fenders flat. And with the new axle being five inches wider on each side than the old one, I don’t really think I’ll have any clearance problems when the tires are turned, either.

So we’ll see what happens Tuesday.