well i know with the metal bits i have i cant. im making a 1/2 mj 1/2 ranger leaf pack. the only ranger leaf im keeping is the main leaf, and putting 2 sua mj leafs under that. only problem is, the new center pin bolt i bought is 7/16 dia, same dia as the ranger centerpin holes. the MJ leafs (as i find out when i get back from the store) are more like 3/8 dia centerpin holes... the 7/16 bolt hex head will fit perfect in the centerhole on the leafspring perch on the axle, so i dont want to buy 3/8 dia bolts as centerpins cuz the hex head will be to small. is there a way i can make the mj leaf centerpin holes 7/16??? im in a bind. this is my dd. i need to get 2 work on monday.. lol

While it is physically possible to drill out spring leaves, it isn't easy.

The spring metal sure isn't mild steel, and requires several drills to get 'er done.

I tried to drill out 1/4 inch holes to 3/8 to do a similar to your project, I wasted MORE than 3 cobalt drills, and finally abandoned the priject, and replaced the springs.

Spring steel is hard !

Ken

I did this on my scout when i did the spring over.
I used an artu 3/8 bit cobalt and tungsten w/ carbid tip
bought it at tool depot in san diego
use cutting fluid liberally (tons) or marvel mystery oil
keep the bit wet and cool ......go slow!

I also heard people used masonry bits in my searching, but I did not try this.

good luck

I use a masonry bit similar to this one...


http://www.cpsc.gov/cpscpub/prerel/prhtml06/06185.jpg

Cuts through it like butter and they are cheap.

A tungsten carbide die grinder on a dremel may be able to widen the holes. It won't be perfect, but should do the job.

I drilled out the center pin to YJ leaf springs. Cobalt bits. Neighbors absolutely hated my ass for the noise :D . Took forever.

Drill press, bits and plenty of lube. Keep the rpms slow.

i used cobalt bits with edge cream it is made by Lbs Labortories it worked great

run the rpms very slow and dont be shy with the cutting oil

I just drilled several springs to build my quarter elliptical packs. Yes the masonry bit works. But my best success was a good quality regular drill bit run DRY on the drill press's slowest speed. Night and day difference between wet and dry. With lube, it would cut awsome for just a little and then dull and stop cutting. A fresh dry bit drilled several springs in a row easily. I know this sounds crazy, but this is first hand experience, I wouldn't have believed it if I hadn't done it myself.

awsome. i was hopeing that people would have experianced this as well. i had never heard of it so i thought i was a dumb question. i will try a masonary bit tommorow. thanks a lot guys

awsome. i was hopeing that people would have experianced this as well. i had never heard of it so i thought i was a dumb question. i will try a masonary bit tommorow. thanks a lot guys

please report back to how easy it is and prove all the wasted dollar, carbide bit buying, slow rpm drilling, oil in out hole junkies wrong. :flipoff2:

well the rearends done. the centerpin holes were drilled via masonary bit. i couldnt find 7/16 so i had to settle with 5/8 (all lowes had). my dads been in the metal bussiness for over 30 years and when he saw me using a masonary bit he nearly shit his pants. well he was proved wrong when he tried using his normal bits that didnt work yesterday. i have a bench gringer so i could sharpen the bit every leaf, and twice for the overload springs. slow rpm was acctualy a must. fast rpms caused the blades edge to chip away. i used cutting oil cuz i couldnt afford any mistakes. i only have 9 dollars till the 14th.. ugh. i bought a BOSCH "blue granite" bit and it boared through the leafs at slow rpms no problem.
dont use a ryobi 10" drillpress. trust me. i ended up going to a buddies house 2 use an ancient drillpress that went too fast and chipped the bit away. i ended up finishing them with a big ass hand drill on a wood block, and the bits garbage now. doing it correct from the start wont destroy the bit. but its done. cost me just under $13.

I bought these after watching the guy run them so hot sparks were flying as he drilled through a file:smokin:
http://www.pirate4x4.com/forum/attachment.php?attachmentid=250658&d=1150733033

die grinder with a cardbie bit works good to hog extra meet out, jason.