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Gun drilled axels

Dirtracer 619

Well-Known Member
Well we are in The middle of upgrading our axel housing, to a floater axel. So new to this type of axel and pricing the axels
I found gun drilled or not. Cost being higher for the drilled No suprise there.

So what does gun drilling do. Help build rpm faster is my guess. But does that make you lose tourque? That you might need going through the silt. Or am i all backwards on this o

Bottom line question is gun drilling worth the added expence

Thanks. Everyone
Gun drilling is a way of reducing weight. Axles are not through hardened typically. So the inner core is dead in spring weight in a straight axle. Irs and ifs the weight is shared sprung and unsprung.
Every lost pound counts. I once knew a drag racer who couldn't figure out why his car always went left. Evidently a 400 pound driver wasn't part of his chassis tuning plan. Put an average weight driver in the car and the problem went away.
Talk to Moore performance in San Diego he can custom machine axles and gear sets. He might give a better reason for gun drilling. For some reason I think it also has something to do with the axle shaft being able to twist and relax with less memory and fatigue being placed on the shaft.


Well-Known Member
I was going to say that the drilling allows them to flex but Bert was already on it So axels won't break

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Heat treatment and metallurgy all have different behaviors in axles. Not all cro-moly axles are the same. Same goes for 1040 1050 300m or whatever the flavor of the day is. You might get away with not running a gun drilled axle if you select the right material. But the whole idea behind running a floater is to let the shaft be a fuse so the expensive stuff can be saved.

Josh 8

Well-Known Member
Maybe this a differnt way to say it.

The inner bore of being drilled creates a sheer location to terminate strees inside the radius.

That probably doesn’t make sense. But by drilling the inner portion of material out making a tube out of the axle it makes it stronger. This is just theory. I don’t really know.

I have always used solid axels to save a buck. But I insisted on using 300m material. It’s basically 4340 with a high amount of nickel. Good stuff.

Sandy Cone makes my axles and he doesn’t really have an opinion when I have asked him. He told me if I want to throw more money at it he can. But it doesn’t make a difference.

Btw. If the inner bore of the axle is just drilled out it would create stress risers and possibly cracks could develop if it is not micro honed and polished internally. Being that the hole is probably 3/4 dia. in a 40 spline axle, I would guess most shops are not honing them out. That’s the other side of the argument.
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Spend some time looking at the front spindles on the big off road trucks. Class 8 and trophy trucks. They are hollow. It's the outside diameter of a tube or bar that gives it the strength. If solid was the answer then people wouldn't go through the hassle of swapping over to dana 44/60 ( or fabricated )spindles on their trucks.

Josh 8

Well-Known Member
Hold on there! These are the ****.


There 300m. This is the legacy line of class 4 morfing into 8. Back in the day the ford guys that converted 4’s to 8’s didn’t rebuild the entire truck. They just ditched the transfer case and differential. In the process they kept the basic Dana 44, 4wd ttb beam and nuckel. Once the stub axle was not necessary they made 300m snouts that were solid. And walla, the 4 just became an 8.
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Saw that kartek makes a set of press in spindles for the 2wd f150. I had started a thread asking about them being used on f100 knuckles. But since we are discussing spindles here I'll ask again I'd anyone has an experience with the kartek spindles and the possibility of using them on an f100. I wasn't saying earlier that nobody used solid spindles. It just appears that most of the kits I've seen were hollow.
I want to ditch my front drums but I want to retain 8 lug and gain the strength of the larger bearing spread and lower bearing speeds brought on by running 2 in spindles and bearings.

Josh 8

Well-Known Member
Well there is could be the difference. This isn’t a production kit. The snouts are made by advanced machine in highland ca. There direct replacement for Dana 44 snouts. So yes. You can use the oem hub, caliper, disk and nuckel. Simply cut the last six or eight inches out of a ttb beam and start fabbing from there. As far as strength, there strong. 37” tires. 135mph top end and hip deep whoops at 90 don’t break them.

There old now. The snouts, Dave and Wally from AMD. Lol
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Yeah. That is what I thought. A one off kinda deal. I've been beating my head against the wall. Do I press out the old f100 spindle and machine new ones. Or do I build an adapter plate that locates off the factory spindle bolts to the backing plate holes and uses Dana spindles and hubs. And build the caliper mounts into said adapter plate. Obviously strength is the concern.