alternator/broke bolt

[mnvalkrider]

Does anyone have an idea on getting a broken bolt out of its hole. Its one of the alternator bolts. The one in the center or outside at 10 o'clock. I have cut a grove in it and tried coersing it with a screw driver but she is solid, now my grove is in pretty bad shape also. I posted ysterday about the alternator and the bolt. Well it turned out that the rotor in the alt is bad so I ordered a new one. But still have the bolt in the case to contend with. Its some hard ass material as I have tried drilling it. That may be my only option now. Not sure what heat would do to the aluminum case.? Tempted to go with two but am sure that would lead to bigger problems. mnrider

[Chrisj CMA]

Have you tried heat? The aluminum case gets HOT trust me you arent going to hurt it with a heat gun.  If you dont have one the local car parts places sell tehm pretty cheap and then you will be able to do magic with heat shrink tubing on your next electrical job.   Ok, but back to the bolt....heat up the case where the threads would be and be patient, try easy outs or a vise grip if enough is sticking out

[eric in md]

two bolts work ..

[Pete]

You may need a special drill bit for hardened steel (carbide I believe) and an ease out to match the drill bit size.  Try Sears or a speciality tool place.

Good luck.

[mnvalkrider]

I like the idea of a heat gun just hadn't thought of it producing enough heat. I was thinking of a propane torch. ugh. I will have to find  a harder bit also . The easy outs are really a problem if they break. Maybe with the heat i will have some luck. I really appreciate the ideas. Its great to have this forum to talk things out!  The two bolts really work?

[Tropic traveler]

Center bolt broken off {recessed in engine case} on my '99 as well. Previous owner had siliconed the broken off bolt head in place. I cleaned that mess up & stuck a chrome plug in the hole. Bought a new bolt from HDL & I'll drill it out & fix it later. For now it's just fine! That was 1,000 miles ago & Lord knows how many before with no ill effects. If you didn't know about Valks I doubt you would even notice it missing!


Don't sweat it, it will have little effect on your Valk!

[Robert]

The heat from a heat gun will not be enough will need a torch and that will discolor the finish in that area. With a good drill bit drill the hole larger by just a bit and retap to larger size bolt. Unfortunately there is no easy way drilling is the best option in a case like this. I think that if you use 2 bolts you'll be fine should have no ill effects at all. If you try the drilling and retapping option you dont have to go all the way down to the bottom of the threads, just go in enough to catch a few threads and cut a bolt to match.

[ricoman]

JB Weld?

[Mr.BubblesVRCCDS0008]

Try heating it up some and then spray some penetrating oil on it and let it cool. The best stuff I've found for this is a brand called Aerokroil. (the oil that creeps) It will draw to the heat and help break the bolt loose. Steel bolts screwed into alum. sometimes build up a white powder corroision. This stuff will break it down. Two bolts will also work till winter comes a long.

[IamGCW]

If you are going to try and drill it I would consider left hand drill bits.  Since the drilling is reverse the screw/bolt will often unscrew as you drill.  Also get the carbide bit, be careful they break easy.  Safety glasses.  Short drill bits are easier to use, I think they are called "Jobber bits".  And if there is room use a guide bushing to keep it centered.  Rig a clamp for the bushing.  Long setup time for a short job, but it often pays off.

[sugerbear]

if some of the bolt is sticking out.   I used these to remove a broken exhaust stud

maybe it'll help you.

http://www.irwin.com/tools/screw-bolt-extractors/7-pc-power-grip-set

 

[Jay]

Mine did the same a few years ago.  I used my Dremel tool with the flex thing and a small carbide bit to slowly drill through the bolt.  Using the same bit, I cut the bolt in half the long way, just up to the threads in the block.  Then used a pick to break the bolt and remove both halves.  Used the original size tap to clean up the threads on all three holes.  Bought three new chrome bolts from Ace Hardware, coated them with anti-sieze and installed.  It took about 2.5 hours, but got it done.

BTW, the Dremel flex thing did not like the heat generated during this and the drive cable broke.  I used the inner cable replacement part for a speedometer cable purchased from NAPA to repair it.

[Baloo]

The same happened to me a little while ago... If some of the threads are still sticking out of the hole ( bolt not broken flush to material) have a good welder weld a nut around it. You place the nut around what's left of the bolt and fill the nut hole with welding. Gives you something to drive the bolt out, plus the heat from the welding helps setting it free. It worked for me... Good luck!

[Tropic traveler]

The same happened to me a little while ago... If some of the threads are still sticking out of the hole ( bolt not broken flush to material) have a good welder weld a nut around it. You place the nut around what's left of the bolt and fill the nut hole with welding. Gives you something to drive the bolt out, plus the heat from the welding helps setting it free. It worked for me... Good luck!

+1
The weld a nut or bolt to the broken bolt trick has worked numerous times for me as well.
Forgot about that one, thanks for the reminder Baloo!

[Grungie]

The Kroil is grate stuff its the best hands down. I us it at work. Adding the heat helps it draw into the threeds. Now if you can us the screw driver and hammer or a punch and hammer to tip on it some, gentely dont try to kill it. The vibration helps the oil get into the threeds. let it set say 15 minutes and repete. This works for me 99.9% of the time. Getting your hands on the kroil may be the hard part. other penatrating oils work well.

[valkmeister]

This happened to me while installing a transmission cover. The bolt broke off inside the altenator housing. It took my mechanic almost 3 hours to drill it out and put a Heli coil in the drilled out mount. It was not a pretty job, and I heard my fair share of cursing. He had to cut one of his drill bits shorter and resharpen it and then use a right-angled air drill to get at it. Not fun! The $120 transmission cover ended up costing me $270 installed!

Good luck with yours.

Valkmeister

[rmrc51]

two bolts work ..

Yep. Mine broke as well and two are holding up just fine.