Found a broken bolt under the HMMWV please help me ID where it cam from

[MarkM]

Found the bolt below under my truck. Not 100% sure it came from the truck. Bolt is about 4" long and has a 9/16" head. Please help id this bolt.

Mark

 

[Black Ops]

That looks like a starter bolt.

 

[charlietango]

That looks like a starter bolt.

Was going to say the same thing


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[dilvoy]

The two rear starter bolts are often over torqued, because of their large size. From memory they only get torqued to about 30 lb ft. Make sure that the starter is supported properly at the forward end by the stud that exits the starter body.

 

[juanprado]

definitely a GM style starter bolt with the special knurled finish on the bottom. Hopefully you have stub left to grab with vice grip. You have a tough job ahead of you.

All the best!

 

[charlietango]

Yep been there done that. Make sure that front bracket is on and snug when you get it back together (assuming the hmmwv used one like the CUCV’s) . Like mentioned above it can be quite the job to remove it if it’s broken flush as the threads mis-shape under torque- why you’re never supposed to re-use starter bolts


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[papakb]

This is one of two 10mm starter bolts. I have had bad luck with buying them from auto parts stores but have had very good luck with the original AMG parts I got from Dave Walker at Walker truck parts in Hesperia, California. I had one of these break and fall out of my truck one day when the truck was shut off and I was halfway thru filling the tank. All the sudden I hear this clink and when I looked under the truck there it was. It's a pure PITA to have to drop the starter and then easy out the remainder of the old bolt, just be extra careful not to damage the threads in the block. Make sure to use locktite when you put it back in and don't overtorque it or you'll end up doing this again.

 

[charlietango]

Oh yeah and make sure the threads are immaculately clean before sending them in with the loctite


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[snowtrac nome]

First off that is a starter bolt 10mm x 1.75 thread pitch if I remember right. This is a common occurrence, a torque wrench is required to install the new one, I would not recommend lock tight on the threads or it will be a pia to get out next time it breaks. If you install them dry it usually only takes a reverse flute drill bit to pull them out.I found the most common reason for them breaking, is a loose , missing or broken nose mount. if one broke than replace them both and also inspect the flywheel ring gear.

 

[charlietango]

Blue loctite is okay in my opinion. I removed one that broke (before I discovered I was missing the front bracket)


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[MarkM]

UPDATE! As talked about it was a starter bolt namely the out board bolt. Was able to move the starter out of the way just enough that I did not have to disconnect the electrical connectors. was able to drill out and easy out the threaded portion of the bolt by using a new cobalt drill bit with a little cutting oil and the easy out. Found a grade 8.8 bolt to get her back together until I get to new starter bolts shipped in. So just where can I get these bolts in addition to the already recommenced vendor. Thanks for the help guys.

Mark

 

[98G]

I bought them at the GM dealer. They don't sell them in pairs. I think I had to buy 5.

You got lucky! I broke multiple drill bits on mine. It took forever and was one f the more frustrating things I've ever done.

 

[charlietango]

Did you have the front bracket installed?


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[MarkM]

Well they are grade 9.6 hardened bolts witch is equivalent to our grade 8 bolts so you really need a real hard drill to cut it properly. People usually don't use cutting oil when drilling and this is a huge mistake as with the cutting oil the bit cuts easier and stays much cooler and lasts a long time. Now if you snap an easy out bit in the hole then get ready for a huge problem LOL.

Mark

 

[MarkM]

Did you have the front bracket installed?


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You mean the bracket that covers the nose of the starter and covers the flywheel access? If so then yes I removed it to move the starter far enough away to get at the bolt tip. I used a piece of wood and a jack stand to keep the starter up and out of the way.

Mark

 

[charlietango]

Wonder what caused the breakage


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[MarkM]

Wonder what caused the breakageSent from my iPhone using Tapatalk

It is a huge heavy starter and secured just at one end. With all the bouncing/shock there is a good load on those bolts and if over tightened it puts a greater load in tension on the poor bolts. If there was a bracket at the tail end of the starter they would probably never break.

Mark

 

[donkren]

This is the bracket that should be on the front of your starter to help prevent the problem you had. If I remember right, it bolts to the engine mount. There is a stud on the end cap of the starter that will engage the hook shaped hole - helps in reinstalling the starter too.

 

[MarkM]

Oh my, I don't have that bracket. Looks like I have to order one of those. Thank you very much.

Mark

 

[86humv]

View attachment 704356This is the bracket that should be on the front of your starter to help prevent the problem you had. If I remember right, it bolts to the engine mount. There is a stud on the end cap of the starter that will engage the hook shaped hole - helps in reinstalling the starter too.

Thats the new style HD one, much better than the thin one, but the thin one is better than nothing.
It mounts to the motor mount cast bracket.