Drilling and tapping ring gear bolts?

threewood · Mar 27, 2015

I bought a set of gears for a 8.75 from another board from a guy going to different gearing. Well, his shop snapped off all 12 bolts. They didn't realize they were left hand threads, all twelve!

He offered all money back or a nice refund. I figured I could give it a go and took the discount. Plan is to drill and tap the bolts to a smaller right hand thread, insert a bolt and twist them out. How hard are these bolts to drill or tap?

Hemi Rebel · Mar 27, 2015

threewood said:
How hard are these bolts to drill or tap?

I guess you are about to find out. Get a good drill bit. Just the act of drilling may back them out. Unless there is loctite on the threads

snakeoil24 · Mar 27, 2015

Drilling out and using smaller bolts will not work. Down sizing these bolts will lead to a failure of the ring gear quick. The bolts are sized to handle the loads that this assembly is designed to handle. Instead take it to some one with a drill press and drill them thru, light heat and easy out. otherwise toss it in the scrapper.

threewood · Mar 27, 2015

snakeoil24 said:
Drilling out and using smaller bolts will not work. Down sizing these bolts will lead to a failure of the ring gear quick. The bolts are sized to handle the loads that this assembly is designed to handle. Instead take it to some one with a drill press and drill them thru, light heat and easy out. otherwise toss it in the scrapper.

I agree. I was going to tap them so I can put a smaller bolt in the busted stud so I can turn them out. Right hand bolt in left hand stud = unscrew by cranking them clockwise.

IQ52 · Mar 27, 2015

There is a good chance they will spin right out while drilling them with a regular right hand drill bit. What I would do is weld a button on the broken bolt, weld a washer to that and then weld a nut to the washer. Should come right out with a box wrench.

dvw · Mar 27, 2015

Their not cross threaded or corroded. They should come out with a right hand drill bit.
Doug

ga66mopar · Mar 27, 2015

You would have thought the person that did this would have figure out something was wrong when he snap off two bolts. Some people

wvmarv · Mar 27, 2015

ga66mopar said:
You would have thought the person that did this would have figure out something was wrong when he snap off two bolts. Some people

I watched a guy bitch bitch bitch while he broke at least a half dozen 1/8th inch drill bits. Then he realized the drill was in reverse. I damn sure wasn't gonna tell him. But I had a hell of time not laughing. LOL.

ZR9B · Mar 27, 2015

they come rite out...don't ask how I know....in my defense, it broke easy.

Meep-Meep · Mar 27, 2015

These are just grade 8 bolts so not hard at all. Make sure you start on center, and to help with that use a center drill in a drill press. It's possible you will have to grind a small flat on the broken bolt to keep the bit from wandering. A #3 or 4 center drill should work fine http://www.use-enco.com/CGI/INPDFF?PMPAGE=50&PARTPG=INLMK32

miller · Mar 28, 2015

Don't use any heat. You can ruin the heat-treatment those gears have.

YY1 · Mar 28, 2015

They are left hand thread for a reason, too.

That shop needs to buy you a good, used chunk, or do the work of extracting the broken bolts.

Cranky · Mar 28, 2015

They do have a dab of Loc-tite on them from the factory but it's usually pretty small and yup, just going at them with a decent sized regular drill bit may unscrew them. Go with a slow speed and a slightly heavy feed and it'll let you know pretty fast if it's going to work. And using a center drill to get things centered and started is a very good idea.

RS23VOA · Mar 31, 2015

Get good drill bits. Lowes bits are garbage. Get you a few bits from Fastenal.

threewood · Apr 3, 2015

Update: Easier to remove than I expected! The bolts were snapped off below the face of the ring and about 6 of them were jagged. The ones that were semi flat I drilled and many of them just unscrewed. The few that didn't seem like they were going to unscrew, I tapped an allen head into the drilled out hole and they untwisted without trouble. The really ragged ones had enough bite for a flat head screwdriver to grab and unscrew. Took about 30 minutes. Now to get it mounted to my new Eaton TT.:happy3:

Drilling and tapping ring gear bolts?

threewood

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Hemi Rebel

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snakeoil24

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threewood

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IQ52

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dvw

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ga66mopar

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wvmarv

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ZR9B

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Meep-Meep

дворянин

miller

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YY1

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Cranky

Banned Henchman #27

RS23VOA

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threewood

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