Alternator Through Bolt Broken in Head

[Snowtrooper1966]

Bolt has snapped off in head.
Not much room to work, maybe an angle drill.
Luckily, it snapped off clean. Just worried that it will be impossible to get a drill bit in the broken stud if it's hardened steel....

 

[Hemi Rebel]

How did it break? When tightening? Or from vibration? The lower bracket with the adjustment slot should have a piece that attaches at the motor mount for support. If it went in ok and the threads are not crossed it will come out fairly easy.

 

[HEMI-ITIS]

You need to get that alternator out of the way.Start with a small drill bit and center drill the broken remains.Then use a lefty drill bit and many times the remains will come out with the drill,if not the extractor bit is next:icon_batman:

 

[jag_mopar]

before you go crazy with the drill, if the bolt was not bottomed out in the hole or rusted, you may be able to walk it around with a small punch and hammer. There is usually a high point on the broken bolt in the hole, be delicate, use it to get a hold with a pointed punch(sharp) dont go too close to the edge as to not stake the broken bolt on the threads, good luck, If not able to walk it out then get your drill and easy out.

 

[Snowtrooper1966]

How did it break? When tightening? Or from vibration? If it went in ok and the threads are not crossed it will come out fairly easy.

Replaced Alt a few days ago.
Must have overtightened it, then vibration from driving today snapped it.

Got lucky, bolt had backed out and was hitting fan blades, but caught it in time before it was a disaster....

before you go crazy with the drill, if the bolt was not bottomed out in the hole or rusted, you may be able to walk it around with a small punch and hammer. There is usually a high point on the broken bolt in the hole, be delicate, use it to get a hold with a pointed punch(sharp) dont go too close to the edge as to not stake the broken bolt on the threads, good luck, If not able to walk it out then get your drill and easy out.

It snapped clean. I may be able to punch a divit off center and try to carefully "walk" it out.

 

[A383Wing]

do you have the spacer that goes in the back?

 

[Snowtrooper1966]

do you have the spacer that goes in the back?

Funny you should ask....
Posted this in another thread a while back...

At least it's an actual car part, just noticed this:

"spacer" on my alternator assembly yesterday.
Previous owner prolly wound up with a MoPar spacer in his Craftsman socket set...

Also see there were wear issues on the through bolt, looks to be the spot the back "ear" of the Alt rests...

If anyone has a source for new bolt and CORRECT rear spacer, I'd be grateful....

 

[A383Wing]

Mega Parts, BE&A Parts, most any Mopar parts vendors carry them...even found on eBay..not that expensive...you get all spacers & all bolts

 

[AMX364]

I think The spacer in question is the one between the mounting ears that should be caught by the slider of alternator. It is pictured in you other picture with parts, next to last on post#7.

edit: which I now notice has broken bolt, so it was installed. I and others have made this common mistake(missing spacer).

 

[b_body_hopeful]

What size socket is that old spacer? Could add it to your collection of tools.

 

[badmopar67]

Seen this done before if you have the room center a nut over the hole and weld thought the center of the nut and weld the stud to the nut and wrench it out.

 

[A383Wing]

just get a left hand drill bit and start drilling. it will walk right out if it's not bottomed out in the head

 

[sleepar]

Left hand drill bit and a use the end of a small file in that hole... if you go the welder route ground it close to the hole or the current can magnetize moving parts so they will attract iron particulate out of the oil as it circulates and damage bearings when current arcs across the surfaces looking for ground.... I would avoid welding on the engine unless all.else fails.... run a tap in there after to clean up the threads.

A spacer made of brass was factory on early cars till they switched to the split steel spacer.... know someone with a lathe?

 

[Snowtrooper1966]

Left handed drill bit?
Are those on the shelf next to the muffler bearings and VW water pumps?

All kidding aside, thanks for the help.
I'll tackle this tomorrow....

 

[bm02tj]

If a store sells chrome muffler bearings they will not stock left hand drill bits

 

[sleepar]

I don't want to reveal all my secrets but .... if you use a bench grinder and smooth off the threads on the bolt you may be able to use it like a screwdriver if the bolt broke with enough lip to catch each other... same as a pick or awl mentioned above... while we're skinning cats

 

[Hemi Rebel]

I don't want to reveal all my secrets but .... if you use a bench grinder and smooth off the threads on the bolt you may be able to use it like a screwdriver if the bolt broke with enough lip to catch each other... same as a pick or awl mentioned above... while we're skinning cats

Thats a good idea. Slicker than eel ****

 

[sleepar]

Left handed drill bit?
Are those on the shelf next to the muffler bearings and VW water pumps?

All kidding aside, thanks for the help.
I'll tackle this tomorrow....

First ask if they have left hand thread lug nuts.... if they roll there eyes at that they stock the blinker fluid... muffler bearings... and have an assortment of STP brand mechanics in a can...

 

[Daves69]

IMO, to break that bolt off there and if it will not turn with an awl, it's likely bottomed at the end of the threads in the tapped hole and will need to be drilled out. Very important to center punch the broken off part in the center! You may have enough depth surrounding the broken end to use a transfer punch to help you stay centered. The first drill should be around .125" diameter then you can increment up from there whether it be a standard or "left" turning bit. How straight and on center you drill that first hole will dictate where the next size drill will go.

 

[conv67bdere]

I bought a alternator relocation bracket at the local car show and installed it with the bolts they provided. Well . . . my neighbor informed me that the nicely polished and chromed bolts that they gave me with the kit were "useless" . . . this was after they broke off - just like your bolt broke off. Luckily . . . I ran a tap in the threads on the engine prior to installing the new bolts, and the bolt busted off at the bracket level - which gave me just enough room to get a pair of vice grips on it and pull them out.

The bolts they provide with the kits might have been grade 5, but with the heating to chrome them, they weaken the metal. I went to the local hardware store and bought a pair of grade 5 replacement bolts, and they've been on the car now for 3 months with not any issues . . . I'll take my neighbors education and never use the supplied bolts from brackets again . . .

Just an FYI . . . thought I'd share a little bit of good advice that I got about cheap bolts with the group.