I suppose this will somewhat walk the line of a "write-up" thread with the Cut and Turn portion in it.
First off, I've never done a cut and turn on an axle before, this was our first. If you're wondering why we took a perfectly good Dana 44 housing and put it to a chop saw, I'll explain. The factory JK housings are plagued with low pinion angle separation. Well what in the hell is that?
Well I'll refer to pinion separation as the angle between the pinion angle and caster. If you're not sure what caster is, there are tons of explanations for that which are better than how I can describe it. Anyway, the JK housing has a 6° of separation. So when the pinion is parallel to the ground [0°], there is 6° of caster. Which is fine when you're stock, but as you start to lift your rig, you're going to run into pinion angle problems sooner than later. The stock driveshaft with it's CV joint is great at eating up driveline vibrations, but as soon as you change over to an aftermarket front driveshaft, you'll be seeing 1-2° caster angles to run a correct pinion angle to keep that driveshaft alive and happy. This makes the rig drive like crap [to many].
To counter-act that, people have been doing cut and turns since the beginning of time, for various reasons. It's not all that common in the JK community, for whatever reason, likely because it's a bit intimidating and requires something to not just to be bolted on.
The other option is to spend the money on an aftermarket housing, such as a Dynatrac has 10° of separation. Which will let you get a nice pinion angle and caster for good road handling at speed, steering wheel return to center, etc. This is a valid option for many, you get rid of many of the factory housing downfalls and are ready to go out of the box! For me, I can't afford to do it, it's really that simple, so this axle is pieced together with various deals, and trickery to go under my Jeep..it'll get me by for awhile.
One of the things we didn't tend to was bracketry. To "properly" do this, you'll want to cut off and rotate all your brackets the same amount you turned the C. Assuming you correct the pinion angle, everything will now be twisted 4degrees from stock. Arm mounts go ~1/8" higher from the ground, springs have a little bow in them, etc. While it'd be nice to do that, I didn't see the benefit outweighing the time needed to do so. So we just turned the C's and I'll deal with it.
As I'm not a "cut n turn guru", we went with what we figured would work after some input from guys that have done it. The sleeves really made things easy, along with the super-awesome chop saw setup.
The process we used for the cut and turn are as follows:
1) Get the bores of the tubes able to accept the Nitro sleeves without fuss. This included lightly deburring the first 3" of the tube, there is some distortion where the C is welded that kept the sleeve from going in. I got it to where the sleeve would go in to, if not almost to, the knurling by hand. After you drill the holes, it'll become tighter from the inside burrs, clean out what you can.
2) Where the sleeves become instrumental to the process was for rotating the housing while cutting and ensuring the C was always concentric with the rest of the tube. Other sleeves have looser tolerances, that would not be as ideal for using them the way we did. Hold the axle up by the sleeves sticking outside of the bore [see pic].
3) Using a OEM Ram spare tire jack, we leveled the pads on the front of the housing [see pic, remove the paint too]. This was out base for every adjustment, don't go changing it, keep consistent with whatever you pick. The housing was set to 90*. BTW, don't use that damn Harbor Freight digital angle finder, it's a piece of crap. We ended up with a big dial version by the time we were done.
4) We cleaned the paint off the top of the C and measured the caster from there, it was 6° [+/- 0.5deg]. We chose to leave the housing at 90° and set both C's to read 10°. We could over-complicate it, stack variables, try to account for floor slope, etc…but really, it's a Jeep on 37s [if not 40s soon], a extremely minor amount of caster discrepancy isn't going to make or break it. Take some "width" measurements for something that isn't moving. We went from the spring bucket to a reference point on the C. Just in case we screwed up and it fell off or whatever, we could reset the width back to where it was. Write it down, you'll forget if you actually need it.
5) Chop saw the C's. We went almost all the way through the tube, I'd say 95% before hitting it to turn. We did this for a couple reasons, one was so we didn't cut the sleeve, the second was to minimize our lateral movement of the C. Allowing the crack to break the C and not the 1/4" wide chop saw blade let us move around the C pretty accurately without the C moving laterally on the housing.
You'll want two people to do this, keep it rotating to keep the cut round. If you can bolt your chop saw down to wood or something, it would have made it easier, as it wants to kick/vibrate away from the housing. With a new blade it clears 100%. If it doesn't you need to get the blade closer to the tube with the saw fully "up".
6) So after rigging the housing so it'd stay put, we scribed two lines to watch and hit away with a 4# hammer. Once it let loose we went back and put the housing to 90° and measured our caster. Once the caster read 10°, we tacked the C back to the tube…make sure you don't tack the sleeve until it's where you want it.
7) After the tacks we knocked in the sleeve, rechecked our turn, and burned it in.
8) Repeat for the other side.
The front end under my rig will now be as follows:
EVo 3/16" C-gussets
EVo Lower Control Arm Gussets
Poly Performance Ball joints
Reid Racing knuckles
Yukon 4.88s w/factory E-locker
Stock, tack'd axle shafts [gasp!]
Riddler diff cover
Nitro hammer-in sleeves, that were welded in
Currie upper control arm johnny joints
Artec truss w/raised track bar mount
Poly Performance drag link
Rock Krawler aluminum tie rod
PSC 1.5" ram-assist cylinder
…I think that's about it.
The housing has it's C-gussets on and I'm trying out Rustoleum Cold Galvanizing paint as a weld-through. I've read online its decent for it and I wanted to get something inside those C's and truss.
I'll update it as it gets in and tested out..