Rear rotor bolts

[Baal]

Okay, I posted this up in another thread, but didn't get an answer.

I am trying to find out what the specs are on the rear rotor bolts on an XB. I know they're Grade 8, button head screws, and that H-D recommends that they be "single use." Other than that I got nothing. The dealer's not going to be able to get them in real time, and ASB won't process an order for just the screws. I've got two good fastener jobbers close, so if someone can post up the size, length and thread pitch, I'll take it from there.

TIA for any help.

 

[BuellerPilot]

One time use, really?? Do you know why?

 

[ophawk]

Part Number CA0005.T
Part Name SCREW 5/16X1.0 BLK SPCL
Retail Price £2.03
Sub Category Harley-Davidson and Buell Parts list

Here you go
Later,
Dale

 

[ophawk]

Here's a pic

Later

 

[upthemaiden]

I tried to pull my rotor off once when i was changing my tire and the first one i tried to loosen just started to twist the teeth in the head. someday when i need them out ill definitely just replace them with some normal grade 8 bolts. mine is a 2003 so ill have to pull it all to upgrade the belt anyway.

 

[Baal]

[up][up][up]

Thanks much, ophawk! If the rep system was working, I'd be throwing you big ups!










wooohooo, 600 posts!

 

[Baal]

Well, interesting discovery or discoveries.

I pulled one of the bolts to go to the fastener shop today. The overall length of the bolt is 1", but the threaded part is only 7/8". So if you go to get replacements without having one in hand, take that into consideration.

Second, getting a straight answer on "Grade 8," which is easy on cap head screws (hex), is tougher on button head screws. I got a Rockwell hardness number, but in trying to get some conversion between that and screw grade (tensile strength) is giving me a headache.

But, I keep going back to trying to figure why Buell/HD would call this a single use bolt. At 27 ft. lbs. mounting torque, it's not like some old cylinder head studs where the installation torque would cause an expected stretch/failure that could not be accomplished a second time (and a high tensile strength bolt shouldn't do that anyway, AFAIK). The only thing I can figure is that the OE screws and the replacements that you can buy are pre-treated with a threadlocking compound, and they don't believe that compound will work properly a second time, and/or locktite won't provide the same "lock" or maybe torque figure.

But, it's been proven a buncha times that I don't know jack. Either way, I've got six nice black carbon steel screws. I suspect that they'll rust; the OE ones are painted, or otherwise treated. I may just get some fresh locktite and go with the OEs

Anybody wanna chime in?

 

[BuellerPilot]

[The only thing I can figure is that the OE screws and the replacements that you can buy are pre-treated with a threadlocking compound, and they don't believe that compound will work properly a second time, and/or locktite won't provide the same "lock" or maybe torque figure."]

EXACTLY what I was thinking!

I'd really like to know this too, I'm about to swap out brake rotors from one set of rims to another and am wondering if it's actually neccesay to get new hardware. I can't imagine these would stretch (ESCPECIALLY being threaded into a much softer aluminum) and was thinking it's just a matter of thread locker, though Blue Loctite has never failed me.

~Mike.......

 

[Baal]

Good BadWeb discussion on this topic HERE.

I'm leaning toward a quick brush-up with a Dremel tool, fresh Locktite, and off we go. (If you do that, crash, and bust your head you're on your own!)

 

[ophawk]

Yeah, I think its the thread locker too.
Just clean them and use new loctite.

 

[Baal]

Done. I took a Dremel tool, gently cleaned the threads, and followed that with brake cleaner; fresh Loctite, and off we go. Now if I was just confident that the doofus at Braking had given me good advice as to the direction of rotation on the wave rotor. Guess I call 'em back. [mad]

 

[Baal]

I had another thought about this. The manual recommends new bolts due to the risk of "losing the mounting torque" or somesuch. The rotation of the wheel would tend to loosen the bolts. That risk probably explains why there's such a large area of threadlocker compound on the bolts when they're new. My answer to that was to apply Loctite farther up (around 1/2-5/8") the 7/8" threaded shank than I ordinarily would. HTH.

 

[BuellerPilot]

Which thread locker you using? I normally use Loctite Blue on most parts. Red is sort of permanant.

~Mike.......

 

[Baal]

I used blue. With the mounting screws being Torx, I didn't want to risk trying to break it loose with a star bit if I used red.