Sheared Alternator bolt, and broken Alternator Bracket
08-02-2017, 11:27 AM
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Sheared Alternator bolt, and broken Alternator Bracket
I've got a 2001 Accord 3L V6 EX. I'm including extra repair details in case anyone needs to do this themselves ~ I'll probably add some more pictures and links later.
TL:DR, My alternator mounting bolt broke, then the alternator bracket broke, and now the mounting bolt broke AGAIN! - All Honda OEM parts from the dealer. Torqued per the recommended spec.
About a month ago the Alternator Mounting bolt sheared in the engine block (Bolt, Flange 10x65 95801-10065-08). The bolt sheared as I was starting the engine, and I noticed something had happened because the belt slipped a bit on ignition, and I noticed a ringing sound from under the hood (the end of the bolt was freely spinning and contacting the automatic belt tensioner pulley, preventing it from just falling out of the alternator). This caused the alternator to only be attached to the engine block by the alternator-mounting bracket (Alternator Stay 31113-P8E-A00).
I ended up driving the car to a shop for an estimate ~5mi, and when I check the bracket again it was slightly bent with the alternator hanging ~10 deg off center. Oops! I decided to fix it myself, as the estimate for extraction and replacement was ~$450!
I removed the alternator and extracted the broken tip of the bolt - not too difficult actually. (I purchased an angle adaptor for my drill [Dewalt 12” Right Angle Flex Shaft], a left-hand carbide drill bit [3-32], and a hex shank to round shank adaptor [DRILL BIT AND ADAPTER SET BY SNAPPY] to drill out the bolt. When I started to drill into the broken bolt, I noticed it started to slip a bit, it was actually pretty loose. I was able to use a dental pick to incrementally turn the bolt shaft back out of the hole, no problem! I would recommend using a left hand drill bit, because if the broken bolt is loose, a regular right hand bit will only spin it deeper into the engine block)
I replaced the broken bolt with the replacement part from Honda (Bolt, Flange 10x65 95801-10065-08 ~$6). Note that the torque spec for this bolt is 33ft-lbs.
About a week later I was accelerating out of a stop light and by accessory belt slipped off. I pulled over and found that the alternator bracket had sheared. This left the alternator attached only by the through bolt that I had just replaced. The alternator was pivoted downward and was resting on the AC line/radiator fan preventing it from ripping out the wiring. I was able to slip the belt back on and limp the car back ~1/4 mile to my work.
I purchased a replacement alternator mounting bracket from Honda and installed it (Alternator Stay 31113-P8E-A00 ~$36). I did have some trouble slipping the accessory belt back on the alternator, as even with the tensioner all the way back, the belt was still too tight to slip over the alternator pulley. I had to remove the alternator bracket bolt so I could pivot the alternator down on the through bolt, put the belt over the alternator pulley and then use the leverage of the alternator to rotate the alternator and belt back up to where I could line up, and thread the bracket bolt back on, torqueing it to the suggested 18 ft-lbs.
So all was well and good until 2 weeks later, I was driving up a mountain in North Carolina and I heard some vibration under the hood. I immediately suspected the alternator. I had my wrench with me and I thought maybe the alternator through bolt had come loose. As I went to tighten it, it sheared with only a slight amount of torque. So I had to drive ~300 mi home with nothing but the alternator mounting bracket holding everything together. After the drive, I inspected the bracket and it seems to be fine, it was not bent and did not appear to be stressed. I removed the alternator and found the broken through bolt to be sticking out of the engine block - I removed it with some pliers, no drill required... lucky me.
So now I'm about to replace this alternator through bolt for the 2nd time (torqued to 33 ft-lbs, no more no less!) and I have no idea how long the repair will last. The details in this thread: https://honda-tech.com/forums/honda-accord-1990-2002-2/alternator-bolt-broke-off-engine-1393645/ And this one: https://honda-tech.com/forums/acura-integra-6/diy-fix-alternator-bolt-keeps-coming-loose-shearing-430603/ suggest this may not be the end of my troubles!
Anyone have some advice/personal experiences?
PS: I checked the belt, and it is the exact same length as the original OEM belt, if not a tiny bit looser, and the belt is tensioned with the automatic tensioner, so I don’t think too much belt tension is at fault here. I replaced the alternator about a year ago, so I think I can rule out the alternator bearings going bad, it spins freely in my hand. Just a design flaw by honda??
TL:DR, My alternator mounting bolt broke, then the alternator bracket broke, and now the mounting bolt broke AGAIN! - All Honda OEM parts from the dealer. Torqued per the recommended spec.
About a month ago the Alternator Mounting bolt sheared in the engine block (Bolt, Flange 10x65 95801-10065-08). The bolt sheared as I was starting the engine, and I noticed something had happened because the belt slipped a bit on ignition, and I noticed a ringing sound from under the hood (the end of the bolt was freely spinning and contacting the automatic belt tensioner pulley, preventing it from just falling out of the alternator). This caused the alternator to only be attached to the engine block by the alternator-mounting bracket (Alternator Stay 31113-P8E-A00).
I ended up driving the car to a shop for an estimate ~5mi, and when I check the bracket again it was slightly bent with the alternator hanging ~10 deg off center. Oops! I decided to fix it myself, as the estimate for extraction and replacement was ~$450!
I removed the alternator and extracted the broken tip of the bolt - not too difficult actually. (I purchased an angle adaptor for my drill [Dewalt 12” Right Angle Flex Shaft], a left-hand carbide drill bit [3-32], and a hex shank to round shank adaptor [DRILL BIT AND ADAPTER SET BY SNAPPY] to drill out the bolt. When I started to drill into the broken bolt, I noticed it started to slip a bit, it was actually pretty loose. I was able to use a dental pick to incrementally turn the bolt shaft back out of the hole, no problem! I would recommend using a left hand drill bit, because if the broken bolt is loose, a regular right hand bit will only spin it deeper into the engine block)
I replaced the broken bolt with the replacement part from Honda (Bolt, Flange 10x65 95801-10065-08 ~$6). Note that the torque spec for this bolt is 33ft-lbs.
About a week later I was accelerating out of a stop light and by accessory belt slipped off. I pulled over and found that the alternator bracket had sheared. This left the alternator attached only by the through bolt that I had just replaced. The alternator was pivoted downward and was resting on the AC line/radiator fan preventing it from ripping out the wiring. I was able to slip the belt back on and limp the car back ~1/4 mile to my work.
I purchased a replacement alternator mounting bracket from Honda and installed it (Alternator Stay 31113-P8E-A00 ~$36). I did have some trouble slipping the accessory belt back on the alternator, as even with the tensioner all the way back, the belt was still too tight to slip over the alternator pulley. I had to remove the alternator bracket bolt so I could pivot the alternator down on the through bolt, put the belt over the alternator pulley and then use the leverage of the alternator to rotate the alternator and belt back up to where I could line up, and thread the bracket bolt back on, torqueing it to the suggested 18 ft-lbs.
So all was well and good until 2 weeks later, I was driving up a mountain in North Carolina and I heard some vibration under the hood. I immediately suspected the alternator. I had my wrench with me and I thought maybe the alternator through bolt had come loose. As I went to tighten it, it sheared with only a slight amount of torque. So I had to drive ~300 mi home with nothing but the alternator mounting bracket holding everything together. After the drive, I inspected the bracket and it seems to be fine, it was not bent and did not appear to be stressed. I removed the alternator and found the broken through bolt to be sticking out of the engine block - I removed it with some pliers, no drill required... lucky me.
So now I'm about to replace this alternator through bolt for the 2nd time (torqued to 33 ft-lbs, no more no less!) and I have no idea how long the repair will last. The details in this thread: https://honda-tech.com/forums/honda-accord-1990-2002-2/alternator-bolt-broke-off-engine-1393645/ And this one: https://honda-tech.com/forums/acura-integra-6/diy-fix-alternator-bolt-keeps-coming-loose-shearing-430603/ suggest this may not be the end of my troubles!
Anyone have some advice/personal experiences?
PS: I checked the belt, and it is the exact same length as the original OEM belt, if not a tiny bit looser, and the belt is tensioned with the automatic tensioner, so I don’t think too much belt tension is at fault here. I replaced the alternator about a year ago, so I think I can rule out the alternator bearings going bad, it spins freely in my hand. Just a design flaw by honda??
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