All 5 drive pulley bolts broke...
Outstanding HDF Member
Joined: Oct 2007
Posts: 3,227
Likes: 5
I don't know what size bolt or the torque specs for these bolts but be careful interchanging bolts ie, grade 5 to grade 8.
While true a grade 8 bolt is stronger than a grade 5 certain conditions must be met. The main condition is torque. If screwing into an alloy proper torque may not be achieved in a soft metal resulting in a premature failure of the fastener. A low torque situation, less stretching of the bolt, will pick up more load than a properly torqued bolt which is also using clamp load to share the load.
We use both grades of fasteners. Our minimum torque capacity for a 7/16" bolt is ~85 lbs foot. We will use a grade 5 fastener at loads less than this. A strectched bolt is a safe bolt and I can't imagine torquing a bolt to 85 lbs foot on my alloy wheels. (Anybody know the torque specs? I don't have my manual here at work.)
And shear strength is ~60% of tensile strength (I do have my engineering books here) LOL.
By all means replace the bolts if changing the pulleys. Grade 5 or 8 is your call.
While true a grade 8 bolt is stronger than a grade 5 certain conditions must be met. The main condition is torque. If screwing into an alloy proper torque may not be achieved in a soft metal resulting in a premature failure of the fastener. A low torque situation, less stretching of the bolt, will pick up more load than a properly torqued bolt which is also using clamp load to share the load.
We use both grades of fasteners. Our minimum torque capacity for a 7/16" bolt is ~85 lbs foot. We will use a grade 5 fastener at loads less than this. A strectched bolt is a safe bolt and I can't imagine torquing a bolt to 85 lbs foot on my alloy wheels. (Anybody know the torque specs? I don't have my manual here at work.)
And shear strength is ~60% of tensile strength (I do have my engineering books here) LOL.
By all means replace the bolts if changing the pulleys. Grade 5 or 8 is your call.
Stellar HDF Member
Joined: Mar 2006
Posts: 3,124
Likes: 255
From: From Long Island, now in So. Cal
small update:
Looks like the first half inch of threads in all 5 holes is gone. Dealer advised me that there is no way the bolts are gonna hold correctly as the wheel sits. Told me to call HD extended warranty company and see if they cover it, sure enough they dont cover anything related to the drive pulley . So unless you guys have an bright ideas, looks like I'm ordering a new wheel.
Looks like the first half inch of threads in all 5 holes is gone. Dealer advised me that there is no way the bolts are gonna hold correctly as the wheel sits. Told me to call HD extended warranty company and see if they cover it, sure enough they dont cover anything related to the drive pulley . So unless you guys have an bright ideas, looks like I'm ordering a new wheel.
Are you sure the threads are missing, or is the first half inch a counter bored hole?
I've heard of this happening before and it is usually after someone puts a new pulley or pulley cover on, as well as ones that have it all original.
I wonder if you have an original untouched bike and verify the pulley bolts torque with a torque wrench that you inadvertently move the bolt which would break that Loc-Tite and cause the bolt to eventually back out.
Which ever way you go (new wheel or not), get new grade eight bolts and clean all your threads with electrical contact or brake cleaner, or any other solvent that doesn't leave a residue, use red Loc-Tite and torque the bolts once.
Tourer
Joined: Jan 2008
Posts: 388
Likes: 3
From: Brunswick, Ohio
happened to me earlier this summer. all 5 were broken off. i drilled what was left of the bolts and used an easy out to get them out. i reused the wheel, but had to get a new sprocket as those were the only holes that were wallowed out.
Outstanding HDF Member
Joined: Apr 2010
Posts: 2,477
Likes: 14
From: Western MD
Just curious how long were your pulley bolts?
When a Indy replaced mine a while back for whatever reason, they installed 1.5" bolts, glad they used new bolts, but it would have been nice if they had used the proper ones. They MUST be 2.25" Grade 5 at least especially on cast wheels.
I had the problem a month ago.
Replaced with 2.5" Grade 8 since they were easy to find.
When a Indy replaced mine a while back for whatever reason, they installed 1.5" bolts, glad they used new bolts, but it would have been nice if they had used the proper ones. They MUST be 2.25" Grade 5 at least especially on cast wheels.
I had the problem a month ago.
Replaced with 2.5" Grade 8 since they were easy to find.
Your a machinist ? Insert the holes , it saddens me somebody has to suggest something this simple and obvious . Guess I've never been in the position were a G note was casual pocket cash 
Using 1 piece inserts not heli-coils done correctly the repair is stronger than stock , you remove the damaged materiel during the drilling operation and the larger OD insert distributes the stress loads better . Your torquing into a steel thread not into a crystallized cast alloy . I do this on high speed / high stress loaded multimillion dollar equipment real regular . Cost is under $100 .....................
Using 1 piece inserts not heli-coils done correctly the repair is stronger than stock , you remove the damaged materiel during the drilling operation and the larger OD insert distributes the stress loads better . Your torquing into a steel thread not into a crystallized cast alloy . I do this on high speed / high stress loaded multimillion dollar equipment real regular . Cost is under $100 .....................
Are you sure the threads are missing, or is the first half inch a counter bored hole?
I've heard of this happening before and it is usually after someone puts a new pulley or pulley cover on, as well as ones that have it all original.
I wonder if you have an original untouched bike and verify the pulley bolts torque with a torque wrench that you inadvertently move the bolt which would break that Loc-Tite and cause the bolt to eventually back out.
Which ever way you go (new wheel or not), get new grade eight bolts and clean all your threads with electrical contact or brake cleaner, or any other solvent that doesn't leave a residue, use red Loc-Tite and torque the bolts once.
I've heard of this happening before and it is usually after someone puts a new pulley or pulley cover on, as well as ones that have it all original.
I wonder if you have an original untouched bike and verify the pulley bolts torque with a torque wrench that you inadvertently move the bolt which would break that Loc-Tite and cause the bolt to eventually back out.
Which ever way you go (new wheel or not), get new grade eight bolts and clean all your threads with electrical contact or brake cleaner, or any other solvent that doesn't leave a residue, use red Loc-Tite and torque the bolts once.
See thats what I'm not sure about. it looks like it could be a c-bore with just rub marks from the bolt but it could also be missing threads. its hard to tell, as I dont know if the wheel is sposed to be c-bored or not. If it is sposed to be c-bored then it would make me alot more comfortable about the wheel. But my stealer acted like there were sposed to be threads there, and said he didnt see the bolts sitting correctly because of the missing half inch.
Last edited by Schaub85; Aug 25, 2010 at 06:58 AM.
Ultimate HDF Member
Joined: May 2008
Posts: 6,642
Likes: 48
From: Ogden, UT
I'm assuming they're the stock bolts. Like i said I've never had them out and havent tried removing them yet.
See thats what I'm not sure about. it looks like it could be a c-bore with just rub marks from the bolt but it could also be missing threads. its hard to tell, as I dont know if the wheel is sposed to be c-bored or not. If it is sposed to be c-bored then it would make me alot more comfortable about the wheel. But my stealer acted like there were sposed to be threads there, and said he didnt see the bolts sitting correctly because of the missing half inch.
See thats what I'm not sure about. it looks like it could be a c-bore with just rub marks from the bolt but it could also be missing threads. its hard to tell, as I dont know if the wheel is sposed to be c-bored or not. If it is sposed to be c-bored then it would make me alot more comfortable about the wheel. But my stealer acted like there were sposed to be threads there, and said he didnt see the bolts sitting correctly because of the missing half inch.
You need to know what was in there so you can figure out what happened.
Unless your wheels are different than others I have worked on, they are not counter-bored. The is a slight chamfer to help locate the threads, but that's it.
Last edited by 8541hog; Aug 25, 2010 at 07:29 AM.
Haven't removed??? one was broken...you can see missing threads...now I am confused....I doubt you could see missing threads through the pulley.
You need to know what was in there so you can figure out what happened.
Unless your wheels are different than others I have worked on, they are not counter-bored. The is a slight chamfer to help locate the threads, but that's it.
You need to know what was in there so you can figure out what happened.
Unless your wheels are different than others I have worked on, they are not counter-bored. The is a slight chamfer to help locate the threads, but that's it.
sorry I ment I hadnt tried to remove the broken bolts. Theyre snapped off about 3/4" in and the first 1/2" of threads is gone. Thanks for the info on the lack of c-bore. confirms the worst.
Club Member
Joined: Jul 2008
Posts: 112,202
Likes: 1,316
From: On a hill among the hills, PA
I don't know what size bolt or the torque specs for these bolts but be careful interchanging bolts ie, grade 5 to grade 8.
While true a grade 8 bolt is stronger than a grade 5 certain conditions must be met. The main condition is torque. If screwing into an alloy proper torque may not be achieved in a soft metal resulting in a premature failure of the fastener. A low torque situation, less stretching of the bolt, will pick up more load than a properly torqued bolt which is also using clamp load to share the load.
We use both grades of fasteners. Our minimum torque capacity for a 7/16" bolt is ~85 lbs foot. We will use a grade 5 fastener at loads less than this. A strectched bolt is a safe bolt and I can't imagine torquing a bolt to 85 lbs foot on my alloy wheels. (Anybody know the torque specs? I don't have my manual here at work.)
And shear strength is ~60% of tensile strength (I do have my engineering books here) LOL.
By all means replace the bolts if changing the pulleys. Grade 5 or 8 is your call.
While true a grade 8 bolt is stronger than a grade 5 certain conditions must be met. The main condition is torque. If screwing into an alloy proper torque may not be achieved in a soft metal resulting in a premature failure of the fastener. A low torque situation, less stretching of the bolt, will pick up more load than a properly torqued bolt which is also using clamp load to share the load.
We use both grades of fasteners. Our minimum torque capacity for a 7/16" bolt is ~85 lbs foot. We will use a grade 5 fastener at loads less than this. A strectched bolt is a safe bolt and I can't imagine torquing a bolt to 85 lbs foot on my alloy wheels. (Anybody know the torque specs? I don't have my manual here at work.)
And shear strength is ~60% of tensile strength (I do have my engineering books here) LOL.
By all means replace the bolts if changing the pulleys. Grade 5 or 8 is your call.
55 - 65 ft lbs cast wheel
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Club Member
Joined: Jul 2008
Posts: 112,202
Likes: 1,316
From: On a hill among the hills, PA
General info on HD grade #5 bolt torque
Fastener Size - Torque ft. lbs.
#8 - 14 in. lbs.
#10 - 22 in. lbs.
1/4 " - 10 ft. lbs.
5/16" - 19 ft. lbs.
3/8" - 33 ft. lbs.
7/16" - 54 ft. lbs.
1/2" - 58 ft. lbs.
9/16" - 114
5/8" - 154
Fastener Size - Torque ft. lbs.
#8 - 14 in. lbs.
#10 - 22 in. lbs.
1/4 " - 10 ft. lbs.
5/16" - 19 ft. lbs.
3/8" - 33 ft. lbs.
7/16" - 54 ft. lbs.
1/2" - 58 ft. lbs.
9/16" - 114
5/8" - 154
Road Master
Joined: May 2007
Posts: 1,168
Likes: 1
From: Cornwall UK
Once a bolt is stretched beyond it's torque limit it's ruined. For the guys who believe you need to put everything on with a 1/2" breaker bar, Metal DOES stretch. I used to work with this moron who constantly had bolts falling out of his Harley superglide. Red locktite on everything and tightened WAY beyond the torque spec. I remember him trying to get a new wheel from Harley because the sprocket bolts sheared off (after he put his aftermarket pulley on). I think the most humorous time was when he was in front of me going to Laconia and his timing plug blew out and oil sprayed everywhere. I guess those timing plugs don't work well being put in with the Ol' locktite and breaker bar menthod either, Lol!!
