Parawhore

Hey guys, new to the site but have spent countless nights reading through some of the interesting posts.

Anyways, had to change a few of the gaskets/seals behind the cam gear and once I had the tower off I came to find the cam bolt had already been stripped by the previous owner. So I got to drilling it out however it doesn't seem to be working. Tried a 3/8 titanium coated bit but it just ripped the bit apart. Went out and bought a 3/8 DeWalt cobalt bit and it got about 1/4 inch into the bolt when the bit began to break apart. Just wondering if anyone has any tips or specific bits that would make it a bit easier. It's taking A LOT more drilling than I thought.

Tom M'Guinn

Something's not right there. I've drilled them before and a good cobalt bit will melt through it pretty easily. Any chance it's an aftermarket bolt that is harder than stock? Many many years ago, a friend was trying to put CB lights in the roll bar of his pick up. He called and asked to borrow more bits because he had been drilling for hours and all of his bits were now dull. When I got there, we discovered that he had been been drilling with the drill set in reverse for hours. Just something to check... Also, sometimes it helps to start with a small bit and work your way up...

Parawhore

There's a pretty good chance it's an aftermarket bolt. The more things I fix on this car the more I realize it's been toyed around with. Not in the best ways either. As for the drill being in reverse. I kept asking myself the same thing. I guess all I can do is keep at it. Am I correct that 3/8 should be large enough?

Tom M'Guinn

Well... it's an M10 bolt, meaning the shaft of the bolt is 10mm. A 3/8 drill bit is only 3/8*25.4=9.525mm, which is just a tad shy of 10mm.

Parawhore

Alright, so after some careful, slow speed drilling constantly cooling the bit with water, the bit became locked in the bolt. So when I went to reverse the bit out it simply turned the bolt with it (go figure).

So I slid the big nut on the end of the gear off without any problem, however now the gear itself will not budge. I'm afraid to pry it too hard because I don't want to damage it. Seem to be stuck again. And from this point the woodruff key looks fine.

arthropraxis

I went through the same thing. You will do better if you use some oil to keep the bit cool and like you said use a slower speed.

Van

Yeah, use a bigger drill bit.

You don't need to go in far - just the length of the bolt's head. Once the head of the bolt is gone, you'll be able to take the pulley off and then remove the bolt either by hand or with pliers.

Should take only a few minutes to have that sucker out.

(p.s. if you've gone pretty deep with the 3/8" bit, you might have cut the threads in the cam shaft... which would make it unusable. If you need a new cam, lat me know - I have a few spares.)

JohnKoaWood

Corrosion between the gear and cam causes the gear to bind up..

Spray some penetrating oil on the cam, and feel free to pry.. I have done a few of them in the last couple weeks, and only had one that slip off nicely!

Once it is all apart, clean up the interfaces using some steel wool with a few drops of oil to "polish" the surfaces.. everything will slide back together nicely!

good luck!

Tom M'Guinn

Tapping (gently) with a hammer can often free it up too.

Parawhore

Thanks for all the tips guys!

Late last night I was able to get everything apart. The 3/8 bit became jammed in the bolt, but when i reversed the drill it turned to entire bolt out with it. No threads were damaged and all was good.

As for the cam gear, I just tapped it gently a few times and wiggled it off. Got everything nice and cleaned up, changed all the seals and will head out tomorrow to grab a new bolt so I can get everything back together. I guess all it takes is a little patience.

Cody.

spanky

Well done!!!