Bolt failure on Alternator mounting bracket

1765 Views 2 Replies 1 Participant Last post by GhostRider, Jul 16, 2017

GhostRider

Discussion Starter · May 26, 2017

Yes we had a hardened bolt failure. A microstructure fracturing propagated by a natural thread root stress riser is the culprit. The shoulder length of the bolt failed to extend into the engine block counter bore which would have greatly reduced mounting face movement frequency. A cardinal design sin... Yes the bolt is what Polaris calls for and it was installed by the Dealer.

Having some left-handed carbide drill bits, I attempted to remove the broken bolt end. As you can see even stepping up the size of the bits would not disengage the broken end threads.

The dealer had to pull the engine in order to get the engine block on a machining center to perform a salvage proceedure?.

Might want to have a look at yours..
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GhostRider

Discussion Starter · #2 · Jun 9, 2017

Update:
Polaris admits error, only after my Dealer fought them for two weeks. Service Manager Madison would not accept anything else. With all the bad stories about Dealers on here, looks like I am lucky to have Ritchie Brothers Polaris in Maryville, TN. All parts and labor covered, a longer shoulder bolt has been specified by Polaris.

If you have not checked to make sure that your Brutus has bolt shoulder contact in the counter bore, expect a failure there. It's easy to check, remove the bolt, verify that the bolt shoulder is longer than the through hole in the mounting bracket.

I will post the new bolt part number when I get it. I hope this post saves some of the members the headache I have been thru...

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