Another Cut and turn (1 Viewer)

[FJ40fiji]

I make no claim as to the correctness of this procedure, It is meerly how I did it to satisfy my own concerns​

I had wanted to cut and turn an axel for a while but was always worried about keeping it the correct width, and ensuring that both sides were the same. This axel was already off of a truck, and in fact was a spare so there was no risk of losing my axel in this experiment. I had seen in some write ups about adjusting one side different than the other by a half of a degree to account for the crown of the road, but as far as I could tell that was not part of the original design ( not that I followed it exactly anyway).

So I built up a jig out of some scrap I had been holding on to for nothing in particular. I thought I'd see what other Mudder's thought of it.

The pictures are after the whole thing was actually said and done. The base of the jig is from a gate (as in to keep people out) I built that was no longer in use and except for the little triangle under the jack was as it has been. It was very closer to flat and square to begin with. the up rights I built out of more tubing form the same gate. They were built just for this and are as square as I can acuratly measure.

The up rights were clamped very securly to the axel housing and welded to the base.

Then I built the T the is mounted to the differential mounting surface. With the axle on the jig I made the neccesary cuts inside the factory welds. It was hard to tell where the two pieces (inner and outer parts of the axel) were actually seperate, and I went a little deep in a few parts, but not critically so. Then I could put the little bottel jack under the T and make small adjustments to the pinion angle and measure with my angle finder along the way.

It only worked pretty well. Even with it all held down there was enough friction in the axel housing through the first few degrees of turning that the whole frame deformed slightly. But I was able to put blocks under it and pull it back to flat with a 4 lb hammer. I still took careful measurements in the typical fashion with my angle finder to ensure that both ends had the same orientation, and that they were where they needed to be relative to the pinion angle. If I use this jig again, I'll add some triangulation, where members will be in tension to resist the torque on the axle and hopefully the frame will not bend.
This set up allows me to apply almost exactly 10000 lbft of torque in a very slow controlled manner with the bottle jack (6 ton). If I were going to do several more axels I'd probably develope a better way to clamp it on as well, but the C clamps stayed secure the whole time so for now they are sufficient.

 

[FJ40fiji]

Oh yeah, in the end I settled on a 72 degree angle of seperation between the pinion and king pin. This allows for 14 degree pinion and 4 degrees of castor. I didn't have any real science behind these numbers. I measured my truck and came up with 24 degrees to point the pinion just a degree lower than straight at the transfercase. I'd like to get a dc shaft, but for now I'll just use 4x4 at low speeds. The castor is based on other peoples reports and write ups. I see alot of recomendations for between 3 and 5 degrees, so I figured I'd try 4. I intend to install this axel in the next month and then see how it works out. If need be I'll cut and turn the one I take out more or less and see how that works.

 

[camcruiser13]

that is some jig you go there, you gonna mass produce c&t's?

 

[FJ40fiji]

that is some jig you go there, you gonna mass produce c&t's?

I am not opposed to helping a few locals do theres, but probably not. There are a few shop's out there that do them already and I really wouldn't beat there price by much. Even with the jig perfected it could be a couple hours to do the cut and turn. Then there is tearing down axles, cutting off turn stops and shock mounts and time to crate them up and ship them. Plus I'd need some kind of insurance before I got into that sort of thing. I am confident in my abilities, but that doesn't mean I won't be found liable if someone wrecks there 40 with my axle under it. I think the $150-$200 other shops charge is pretty fair (fair doesn't mean I can afford it right now though)

 

[mtweller]

Good points....too bad I am not a "local"

 

[FJ40fiji]

Not to sound jaded, but it sure seems like a good bit of the wheelin community is local. I am actually from NC originally ( Ashville). I'm in central CA now though. Unfortunatly I only know a couple of local cruiser heads. I have pm'ed a few guys about meeting up in the past to no avail. I'd probably have more luck if I actually got my truck ready and did some wheelin. Of course my old lady would get upset cause it would take time away from us, and then my cruiser buddies would go the way of my drinkin buddies ( I sure miss those guys).