New member with Cam Bolt Issues

[StaceyQ944]

So I have the dreaded stripped cam gear bolt.....

What are the tips and tricks to get that sucker out? I know it’s in at 50 ft lbs so it’s going to be a bear to get enough bite on it. I REALLY don’t want to drill it out.

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[Tom]

Honestly, it's one of the easiest bolts you'll ever drill out. Use a bit just a little larger than the bolt threads -- so if memory serve a 7/16" bit would do it. You just drill until the head pops off and spins on the bit, then stop. You don't need to drill down past the head, and the triple square socket will center your bit for you. You can put some damp rags under it to keep the shavings contained and use a magnet stick to pick up anything you miss. You can then pull the cam off and 9 times out of 10 the bolt will just screw out by hand or, if needed, with vice grips.


You can try pounding a torx bit in there, and welding a nut onto it always works too, but drilling the head off is super fast and easy. It's not like a water pump bolt where you have to drill down the length of the bolt to get it out. Just pop the top off it, remove the pulley, and the rest of the bolt will then be easy to get out. Whatever you do, don't try to dill down into the bolt for an EZ-Out. That thing will snap inside and just make the problem thirteen times harder to fix...

[StaceyQ944]

Thank you for setting my mind at ease with that explanation!!

Do you have a suggestion on the type of bit I should use? I’m sure the bolt is hardened steel so I’m thinking cobalt.

[stitch2k1]

+1 pound a torx bit in, try to get the bolt out the old fashioned way before drilling. I would be weary of unintentionally damaging the camshaft, especially if you're new to this.

[Tom]

Thank you for setting my mind at ease with that explanation!!

Do you have a suggestion on the type of bit I should use? I’m sure the bolt is hardened steel so I’m thinking cobalt.

I always go for Cobalt on steel bolts.

As for damaging the cam with the drill, I think you'd almost need to try for that to happen. I just went and tested a little on my spare motor. I'd suggest a 13/32" bit. The head is about 6.5mm thick, so it should pop off and start spinning when the bit gets that deep. If you kept drilling anyway, the next thing you'd hit is the landing inside the dog nut. That landing is about 5-6mm thick, so it you drilled too deep you risk putting a little chamfer in that landing/washer area inside the dog nut. If you really butcher it, a new dog nut is easy and cheap to get on ebay... If you kept drilling past the dog nut, a 13/32" bit actually fit into the bolt hole well on the end of the cam, so you'd need to push in beyond all reason (an additional 32mm) to actually hit the threads in the cam. Pure speculation, but pounding a Torx bit would also seem to risk the creation of gasket/seal leaks....

Edit: of course this all assume that you drill straight. When I've done it, the stripped bolt head serves as a guide and keeps the bit straight enough, but if you went in on a harsh angle you'd still need to drill all the way through the dog nut to get to the cam....

[StaceyQ944]

Thank you for setting my mind at ease with that explanation!!

Do you have a suggestion on the type of bit I should use? I’m sure the bolt is hardened steel so I’m thinking cobalt.

I always go for Cobalt on steel bolts.

As for damaging the cam with the drill, I think you'd almost need to try for that to happen. I just went and tested a little on my spare motor. I'd suggest a 13/32" bit. The head is about 6.5mm thick, so it should pop off and start spinning when the bit gets that deep. If you kept drilling anyway, the next thing you'd hit is the landing inside the dog nut. That landing is about 5-6mm thick, so it you drilled too deep you risk putting a little chamfer in that landing/washer area inside the dog nut. If you really butcher it, a new dog nut is easy and cheap to get on ebay... If you kept drilling past the dog nut, a 13/32" bit actually fit into the bolt hole well on the end of the cam, so you'd need to push in beyond all reason (an additional 32mm) to actually hit the threads in the cam. Pure speculation, but pounding a Torx bit would also seem to risk the creation of gasket/seal leaks....

Edit: of course this all assume that you drill straight. When I've done it, the stripped bolt head serves as a guide and keeps the bit straight enough, but if you went in on a harsh angle you'd still need to drill all the way through the dog nut to get to the cam....

Thank you for that detail.
I settled on the 13/32 as well. I just had to order one since no local stores carried that size and all I had was titanium nitride. I also has to get a 90 degree drill so I could get access with the cam tower still in the car.

I plan on attacking thing tomorrow some time when the hunny do’s are finished. I’ll keep everyone posted.

[StaceyQ944]

Success!!!

13/32 cobalt stubby bit worked like a charm. That bolt is a bit of a bear though. It took the outer point edge of one of my bits. The bit is still sharp and should work on softer metals, but I had to get a second to start cutting again. Not a biggie since I had one.

Thanks to all for the advise and tips!

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[Tom]

Awesome! Did the bolt spin out by hand? A lot of times they do that.

[StaceyQ944]

Awesome! Did the bolt spin out by hand? A lot of times they do that.

It sure did.
My 14 y/o son who is my garage helper and car lover was amazed at that part. It was a great learning opportunity for me to teach about how bolts and screws work and when you release the tension it’s just a threaded rod with no force/ stretch holding it tight.

I had a 69’ Beetle for many years and rebuilt it. He was too young to learn then. He was the reason I bought the 944. He was begging me to teach him to work on cars. I figured I might as well get something fun and at least 37 years old. And I’m talking about cars......

[Paul M]

I've got the same problem. I really appreciate this thread. I'll attempt this fix tomorrow. Just wondering what's the best way to avoid the issue?

I started torquing in a new bolt (after seal replacement) with a 6-point 8mm and could feel it start to slip. It hasn't totally stripped, but I swear it had that terrible mushy feeling around the 35-40 ft lb range... still got 10 to go

Is a 12 point necessary? Seems odd these are so easily damaged. Any advice appreciated.

Paul