Gun Drilled Axles

[corvette66]

What is the deal with the gun drilled axles, I know what gun drilling is, but what are they doing to the axle exactly, and why is it so much better than stock?

 

[Ken]

Well, you won't have to worry about gun-drilled axles on your '86, but if you had a solid axle Corvette, there is a benefit of lighter weight when utilizing gun-drilled axles. You won't find them on street driven cars for the most part.

 

[Tom Bryant]

Maybe one of the engineers on here can explain it better than I can but in addition to weight savings here's my understanding. A gun drilled axle in effect turns a solid bar into a very thick walled tube which has superior strength in relation to breakage from twisting.

Have you ever noticed that when you twist off a bolt there is a small spike of metal in the center of the break? Twisting the bolt, or axle in this case, applies more twisting stress to the molecules at the center of the bar, trying to compact them, than to the rest of the cross sectional area. As you go from the center out to the edge the stress is less. Therefore the break begins at the very center of the bar. By gun drilling the bar you have eliminated the area in the center of the bar where the most stress concentrates spreading out the stress over the greater outer area of the bar. This also reduces the ability of the bar to twist over the length of the bar from torque applied from the differential and results in a much stronger axle.

I don't know all of the engineering terms but this is the jist of the deal.

Tom

 

[Ken]

I ain't no engineer, that's for sure, but I can research stuff and present it for discussion.

TOO HEAVY?
Moser Engineering can now gun drill and add lightening holes to any 35 or 40 spline M/E Custom Alloy Axle we sell. This will allow you to obtain the strength of the 35 or 40 spline axle without adding all of the weight that comes with the larger shaft.

So, the strength is already there with the 35/40 sline axle, but if I read that correctly, gun-drilling simply lightens the load, eh?

From Mark Williams:

When gun-drilling is desired, MW also includes lightening holes in the flange. These operations results in a weight savings of approximately 17% over standard MW "Hi-Torque" axles.

Seems to me that gun-drilling is for lightening purposes more than anything else, Tom.

 

[MaineShark]

Tom: almost. The hollow tube is stronger than the solid bar, if both are the same weight. If they are the same outside diameter, the solid bar will be stronger. But it will also be heavier, and that's not something that people want, in a performance car.

Joe

 

[Jack]

I see gundrilled axles in many open wheel sprint cars and in upper classes of asphalt circle track late models & supertrucks. I understand gda's can be accelerated more quickly than solids ... something to do with angular momentum. Unless they get some high$ heat treat, gda's break much more easily. Can't see em holding up in a relatively heavy vette ... wouldn't work in 63-up irs anyway ... gda=race only.
JACK:gap

 

[corvette66]

Yeah thats pretty much what i figured, but I wasn''t positive.