O.T. Jeep CJ-10a conversion project

[1x1_Speed_Craig]

As many of you know, I am getting one of my CJ-10a Flightline Tugs ready for plowing this Winter. I have a 2nd tug that I'm converting for road/offroad use (this is Marine-OpLaw's old tug). I'm excited about this project, as it doesn't require a complete ground-up build. Time is a commodity for me right now, and this tug ran/drove well (up to ~18 mph) prior to me pulling the rear axle and bobtail bed. My plans for this tug are relatively straightforward, and include the following:

• Keep it on the cheap by bartering for parts where I can.
• Retain stock Nissan SD-33 6-cyl. diesel motor and TF-727 auto transmission.
• '90 GW Dana 44 front axle: I'm in the process of cleaning this axle up for paint; see photo below. It'll need a 4.10 re-gear, and I'd like to convert it to manual lockouts and add a locker. I'll see how the budget goes. This axle is a bolt-in for the '10a (translation = easy swap).
• Isuzu Rodeo Dana 44 rear axle: Cooter scored me one of these, and I'm getting it in trade for some Scrambler parts. It has 4.10 gears, rear disc brakes, 6 x 5.5" lug pattern, and it's ~58" wide WMS-to-WMS. It'll be a great match for the NT FSJ front axle.
• Plain-Jane Toyota 4-Runner steel wheels: Free from Mr. Stabby (I owe you one, Joe). These have a 6 x 5.5" bolt pattern, and I love the ultra-basic style of this wheel (it retains basically the same look as the stock 8-lug military wheels that came on the '10a). I'll just blast 'em and paint 'em black.
• NP-208 T-case: I swapped an NP-229 case for this one (thanks 46flattie). It'll replace the AMC 198 case that's currently in the tug, and locked in low-range. The 208 is a bolt-in affair, and I'll just need to extend the shift linkage by ~4"...an easy fix.
• 32" x 9.5" Swampers: I also got these from Cooter on trade. The size will allow me to retain a stock height, and not have to buy a lift kit. NOTE: Even with a lift, the front tire size using the stock CJ-10 front fenders is limited due to the wrap-around in front.
• Reworked rear springs to extend wheelbase (see more info below).
• Flatbed rear w/a cage of some sort. I hope to talk with the JCR guys about this, maybe sometime next Spring.
• Pintle hitches front & rear.

The existing rear spring setup (check out those monster rear leafs) are all FSJ, outboarded w/56-57" spring packs (HD of course, for this application). The stock setup is SOA, with an off-center pin. Reversing the spring will move the axle back about 5 1/2" over stock, but that's not far enough for what I want. Instead, I'll be installing a 2nd set of front FSJ springs, and relocating them under the frame rails. This will require an SUA setup to maintain the existing ride height. By going under the frame rail and using the front Waggy springs (2" pin offset), I'll be able to move the rear axle back roughly to where the tire is positioned in the photo below. I considered switching to 63" Chevy springs, but they'd be too long for this frame setup.

Anyway, I'll be working on this project over the Winter. The only attention the tub will require is the repair of a tiny (smaller than a dime) hole in the passenger floorpan. Other than that, it's all rust-free.

So there it is. This project will require substantially less work than a full frame-up build, but will still be a unique and rust-free Jeep that should probably get 28 mpg with the 6-cyl. Nissan diesel motor it has.

Craig

 

[1x1_Speed_Craig]

Here's a pic of the tug in stock form (prior to pulling parts off). I just ordered a set of these Sky Manufacturing spring hangers, and some JC Whitney 5-leaf Waggy springs (PN# ZX072047B) to mount on the rear of the tug.

I got the track bar bracket removed from the front Dana 44 axle, and I'm still working on wire-wheeling it (lots of nooks & crannies on a front D44). I'm also working on wire-wheeling the NP-208 t-case, and have it about 50% done...bling, bling.

More pics to come...

Craig

 

[trust]

Sounds cool Craig, have you checked the toyota wheels yet? I tried to use a set on a Bazer some years ago and while the pattern was right, they didn't fit the brake calipers (or something).

Just a thought

tr

 

[ryankopecki]

I like this build. I've been thinking of doing one myself but don't have a use for it. Like to see how it turns out. I think that's a great choice of tires.

I think you may be making a mistake going with the 4.10 gears. I'm not sure how that diesel likes to rev but I could see your top speed being 55mph or less. At 55 you'd be turning about 2500 rpm. I'd be looking for something more like 3.08 gears.

 

[1x1_Speed_Craig]

Sounds cool Craig, have you checked the toyota wheels yet? I tried to use a set on a Bazer some years ago and while the pattern was right, they didn't fit the brake calipers (or something).

Just a thought

tr

The register, as I have been told it's called (center wheel opening), is a little bigger on the Toyota wheels, but the bolt pattern is the same. The wheels clear the calipers on the '90 Grand Waggy Dana 44 just fine (thankfully).

Craig

 

[1x1_Speed_Craig]

I like this build. I've been thinking of doing one myself but don't have a use for it. Like to see how it turns out. I think that's a great choice of tires.

I think you may be making a mistake going with the 4.10 gears. I'm not sure how that diesel likes to rev but I could see your top speed being 55mph or less. At 55 you'd be turning about 2500 rpm. I'd be looking for something more like 3.08 gears.

Thanks Ryan. Several people on the CJ-10 list have swapped out their 4.88 gears to 4.10s for daily driving, and are happy with the results. There have been several discussions on that Yahoo Group about gear calculators, diesel performance, etc. I went with 4.10s based on this feedback, and the availability of a stock D44 that I wouldn't have to regear and would be the right width/bolt pattern.

Besides, I probably won't be doing much high-speed highway driving with it anyway. My commute to work is all surface streets.

Craig

 

[canzo]

Sounds great, Craig. Can't wait to see the finished project. There was a guy at Oak Ridge that had a 10 with D44s. Very nice.

28 mpg is a big plus! And then, if you make your own diesel, you'll be saving even more money.

 

[1BADCJ8]

10's are way cool. Glad I driffted over tonight and saw this. That would be a very fun build.

Stretch the wheel base a tad with a flat bed and 37's, that would be quite cool.

 

[1x1_Speed_Craig]

UPDATE:

The 4-Runner wheels are now painted (POR-15/POR self-etching primer/Krylon topcoat), and I'll be getting the 32" TSLs mounted on them shortly. The front Grand Waggy Dana 44 is with my friends at Five Star Auto, getting rebuilt with 4.10s, Detroit Truetrac, new bearings/seals/ball joints, etc...I'm trading this work for technical writing & website update work.

The rear springs I selected are actually another set of front Waggy springs (from JC Whitney). I got the rear spring hangers aligned and tack-welded on last night. It looks like I'll have to outboard the rear shackle hangers 1", as the rear portion of the frame is narrower than where the front spring mounts are located.

Tonight, I'll finish removing the other spring perch from the Isuzu D44 rear axle, and get it hung underneath the tug.

Exxxxx-cellent.

Craig

 

[kohldad]

Looks like a fun project.

Bad timing for me though. Do you have a good web site where I can learn about the stock form of a CJ-10a pretty quick to know if I want to buy a couple of good deals coming up?

 

[1x1_Speed_Craig]

Looks like a fun project.

Bad timing for me though. Do you have a good web site where I can learn about the stock form of a CJ-10a pretty quick to know if I want to buy a couple of good deals coming up?

Eric,

I put together this thread when I first bought MarineOp-Law's CJ-10a. Most of the info was pulled from the CJ-10 Yahoo Group. Hopefully, it helps you out. Feel free to e-mail me (one.x.one.craig@gmail.com) with any specific questions you have.

Craig

 

[1x1_Speed_Craig]

With the help of my friend Wingnut (from a local Jeep board), we made some good progress on the tug over the past day. The transfer case is now removed, and the NP-208 will be going in shortly.

The rear axle is now sitting under the vehicle, too. I have to say, reusing the spring perches made the removal process slow & tedious. I decided to run the Waggy springs with the short end on the front, which allows me to use the original shackles and shackle hangers, just flipped over from the original orientation. Since I flipped the springs around, the wheelbase will be right around 96" (about 2" longer than a stock CJ-7).

Craig

 

[1x1_Speed_Craig]

The axle is now hung under the Jeep, and the rear shackle hangers are tack-welded in position. With a full tank of diesel (20 gallons) and 140 lbs. of sand bags on the rear to account for a bed of some sort being added a little bit down the line, the rear shackles have a nice angle. The new rear springs will also settle a little with use. I still need to fine-tune the side-to-side adjustment of the axle position, as well as setting the pinion ange properly. The front end sits a little lower than the rear, so I ordered a set of HD lift shackles from bjsoffroad.com for the front. Those should balance out the stance nicely.

I also got the tires mounted on my Toyota rims. They're topcoated with gloss black Krylon, but after seeing them next to the vehicle, I may hit them with a top coat of semi-gloss instead. Opinions? I'm just wondering if they look a little too shiny. The frame & axles will definitely get semi-gloss. They probably just look extra shiny to me because the frame is dirty and not painted yet.

Next steps...

• Install front lift shackles once they arrive.
• Finish tweaking the rear axle positioning.
• Install the NP-208 t-case.
• Talk to the a local shop (jcroffroad.com) about doing the finish welding on the suspension components (I can do nice flat welds when I can rotate the frame around, but my vertical & overhead welds need practice). I know that the welds will look great if the JCR guys do them, and I'll also have them double-check all my measurements & suspension setup.

Craig

EDIT: Cooter votes for satin black for the wheels. I'm thinking that I'll definitely go less bling than what they currently are.

 

[Jeepskate]

Coming along *real* nice, Craig. The gloss black is def too much...semi or satin.

 

[Truck]

Craig, it is looking good. I wish I had the time to push my own projects along so well. Yea, gloss is shinny, but once you buff out the tub and clean everything up in might not be so bad, but a lower sheen won't show the dirt as bad day to day.

Truck

 

[trust]

Craig,
I'm Very impressed with your progress, I am struggling to complete even the most mundane tasks on any of our vehicles these days much less anything significant, fortunately I can now blame it on the snow.

I wouldn't worry about the gloss on the wheels, I doubt it'll last unless you keep it waxed and buffed.

tr

 

[1x1_Speed_Craig]

BTW, upon prodding from Cooter, I test-fit a set of 34" x 9.5" Swampers that I have on another Jeep, and it looks like they'll fit (I would have sworn they wouldn't). Of course, I find this out after I paid to have the 32" Swampers mounted. Stay tuned...pics to come after I get the 34s mounted & installed...

Craig

 

[kohldad]

Bad timing for me though.

I stand corrected for some strange reason.

Seems like great timing and a good resource what may be my next project.

Have to agree that those black glossy rims just don't cut it. They will fade some but will take a while.

 

[kohldad]

Craig, in case you were interested, thought I would pass this link to you. It is the hp and torque curves for the Nissan diesel. I had been under the impression that the 4.10s you picked would have the engine rpm to high. But the chart and specs in the link show a 3800 rpm max and about a 2800-3000 rpm cruising value. This should put 32" tires able to cruise right at 60mph without an issue.

Nissan 6-33 Diesek Performance Specs

 

[1x1_Speed_Craig]

Craig, in case you were interested, thought I would pass this link to you. It is the hp and torque curves for the Nissan diesel. I had been under the impression that the 4.10s you picked would have the engine rpm to high. But the chart and specs in the link show a 3800 rpm max and about a 2800-3000 rpm cruising value. This should put 32" tires able to cruise right at 60mph without an issue.

Nissan 6-33 Diesek Performance Specs

I thought it would be close with the 4.10s. That's the turbo version, so there will be a slight differece. Also, I decided to go with the 34"x9.50" tires (barring any final clearance issues), so it'll have a little more high-end. This won't be a daily driver or a highway driver, so I'll trade off some practicality for performance. Gear selection was also dictated somewhat by cost. 4.30s are expensive, while 4.10s are common. I ended up getting my Rubicon 4.10s (for the front) for free from a friend who had a BUNCH of sets lying around.

BTW, binderbulletin.org has a GREAT diesel forum. It sounds like you may have already found that resource, though.

Good luck with the tug project(s), Eric, and let me know if I can be of assistance with parts manual info (part #s, etc.).

Craig