Drill a hole in a leaf spring?

Saw a kit available as an overload setup, it basically puts a removeable steel pad on top of the shortest/thickest leaf, that way it touches the main (softest) leaves early. Okay, makes sense. But to install it means drilling the thick leaf, the kit even includes bits (yes, plural, looks like they plan for them to wear out). What's the best way to do this?

Carbide, slow rpm and lots of oil?

Buy a different kit.

Air Bags

The kit requires drilling for centering bolts, that keeps the mount pad from getting shoved off the spring. Makes sense to me. That mount pad stays in place, the spacer that does the real work goes on top of the mount pad is quickly removeable, take 'em off and stick 'em in the trailer when not needed. On this one, you just spin them out of the way:

I looked into air bags, I'd have to custom fabricate brackets etc.

CnT you use the bolt on above axle overload leafs. When not needed you could just disconnect one end?

I'm lazy, I like quick disconnects. I got to looking around the int3erw3bs, I might see if I can cut down some urethane Jeep bump stops and use those. Still have to come up with a bracket that won't slide on the stock overload spring, though.

Something like that yellow bracket should be easy enough to build that would slide on over the end of the spring and be held in place by a bolt or pin on each side of the spring that fits into a notch in the side of the spring instead of a hole in the middle. Grinding in a couple of notches would be a ton easier than drilling holes.

Or build something that looks like a really long spring shackle to sit horizontal with the bolt/pin on each end going between the bottom leaf and the rest of the stack, one bolt/pin in the gap on the front of the spring and the other in the gap in back. You could probably slap that together with 4 tractor top links and pins in about 10 min for $80.

Here is a thread with good info. http://www.practicalmachinist.com/vb/general-archive/drilling-spring-steel-87023/

Slow speed heavy feed, lots of oil. Spring steel isn't super hard, its just tough and will workharden fast.

The cheap carbide tipped masonry bit is an interesting idea.

I've found that carbide tipped drill bits are only good for masonry use. Drilling steel is for steel/titanium bits and just keep the drill speed as low as possible.

oldopelguy wrote: Something like that yellow bracket should be easy enough to build that would slide on over the end of the spring and be held in place by a bolt or pin on each side of the spring that fits into a notch in the side of the spring instead of a hole in the middle. Grinding in a couple of notches would be a ton easier than drilling holes. Or build something that looks like a really long spring shackle to sit horizontal with the bolt/pin on each end going between the bottom leaf and the rest of the stack, one bolt/pin in the gap on the front of the spring and the other in the gap in back. You could probably slap that together with 4 tractor top links and pins in about 10 min for $80.

I'm kinda thinking this: a long bar below the big leaf that's clamped by the U bolt bracket, holes outboard of the spring on each end, use that to keep my spacers from sliding. Easy to fab and won't change the ride height when the spacers are removed.

KyAllroad wrote: I've found that carbide tipped drill bits are only good for masonry use. Drilling steel is for steel/titanium bits and just keep the drill speed as low as possible.

The practical machinist folks say that there is no relief ground into the tips of carbide masonry bits. They suggest resharpening to 118 degrees with some good relief behind the cutting edge and they will work.

Coming from the "WHOA three of my leaf springs have cracks in them" guy, I am not sure I'd be excited about drilling holes in them, hard to do or not. I think a fella like you could probably out-clever them with a few hours worth of imagineering.