thrashingcows

Not really 1st Gen related, but guess we could say it's for a snapped bolt on a 518.... I bought some used engine cases to repair the motor in the 97 Big bear quad I bought a few months ago. The used cases has several M6x1 bolts snapped off flush in the aluminum case. I have managed to get two of them out with left hand drill bits, but the others are not budging.

Just curious what type of extractors you like to use and which are more effective then others, types, brand etc?

Thanks....

Foxmxrcer

Got a mig welder? Weld a nut to it... Nothing works better imo. Other then that, I've had terrible luck with all extractors... But the best luck with the fluted drill bit looking ones.

maybe368

I usually end up carefully drilling a small hole in them, as close to the center as possible. I then go to bigger bits until I can collapse it into the hole and thread it out. I have never had good luck with extractors. I once welded a steel bar to a caliper piston on my Porsche 912 to twist it out. Even then it wasn't easy...Mark

NJTman

That's an awesome way to go with bolts stuck in steel. I'd be a bit wary doing that in an aluminum transmission flange.

My personal experiences with aluminum with bolts stuck in them has not been good. the hole in which the bolt is stuck in, nearly almost always gets out of shape, and loses it's center. Using a die grinder with a carbide bit to hollow the bolt has helped me out as well

Foxmxrcer

I've honestly never had a problem. Using the proper size nut will prevent damaging or melting. And as a second line of defense, you can weld a washer to the stud first, which will act as a shield... Then weld the nut on. Buy, if you think about it... You have to be just as careful with steel, as you do with aluminum... What happens when your mig wire touches the steel? Welds the broken stud to the head/block/whatever you're drilling

NJTman

True, TC has flush broken bolts (no stud)of a m6 size. I'm not technically capable to weld a nut on something that small

Foxmxrcer

M6 is pretty small... That's where the washer trick comes in. Weld the washer to the flush broken bolt/stud, then use a larger (like 8mm or even 10mm) nut, and weld that to the washer

peckens

Once you weld it let it completely cool. I always warm up aluminum with a propane torch before trying to turn something that might have corrosion. You can also take a hacksaw or file a cut a slot into a screw then back it out with a flat head.

BHD

That's how I remove broken fasteners in GM aluminum cylinder heads, especially 6.0L, on the vehicle. I have found washers are best, you get a better heat sink to the broken fastener and then again to the nut on the outside.

MrFusion

I agree with welding. Done it a few times with decent success. If that is not an option would you be able to Helicoil it?

thrashingcows

don't think there is enough material for a helicoil, they are on the outside of the case and a raised boss.

I have been heat cycling them for days now, with alternating PB blaster and other release type agents. I am dismayed that there has been so little success with extractors....but I think I will try the fluted style and really take my time trying to get them out.

Thank you all for your responses!

oliver foster

Thrashing I had 3 broken off fan hub bolts in my '95 dually a few months ago. I found out when the fan and hub went through the radiator while on a road trip 4 HRs from my house.
They busted off basically flush with the block

My friend recommended using a reverse thread drill bit. I used a slightly smaller bit then the bolts. Two of the three spun right out as I drilled them.
The third I had to drill completely out, then clean up the remaining bolt bits out of the threads and re tapped it.

PS I just read that you tried the left and bits already....at least we where thinking alike.

Alec

For what it is worth, on something that small, I would try the parallel spline type extractor. If you have already drilled the bolt, it may not work, you really have to drive them into the correctly sized hole. With luck, they will bite without expanding. With the tapered style, I break the extractor if it is too small, but then they tend to expand and jam the fastener if you drill it out enough for a big one.

If you have a mig with fine enough wire, drilling and welding is the way to go.

edwinsmith

This makes me think a left-hand straight reamer the right size would also do in a pinch.

thrashingcows

I have only drilled to about 1/8...maybe a tad smaller. I'm going to try this style and see what happens.



I picked up the longer fluted style today, but after some more advice I think I will return those and try the above type. Will update on how they work.