Broken cuff bolt

[Deye76]

And the gorilla strength lockpatch has caused more than a few of those bolts to break while being removed. Heat helps a bunch, as does patience, when removing them

Funny I've read on here more than once that those lock patches don't do anything. 

Are they for sure pre applied patches? Doing a search of pre applied Loctite products show a max temp of 392 deg F. Maybe I missed some that are rated to higher temps. All I know is the pre applied yellow stuff that comes on S&S backing plate screws turns to powder upon installation.

[Ohio HD]

The pin in the Twin Cam is a better idea. You can set the clearance as you please, and the pin just lifts out.

[kd]

And the gorilla strength lockpatch has caused more than a few of those bolts to break while being removed. Heat helps a bunch, as does patience, when removing them

Funny I've read on here more than once that those lock patches don't do anything. 

Are they for sure pre applied patches? Doing a search of pre applied Loctite products show a max temp of 392 deg F. Maybe I missed some that are rated to higher temps. All I know is the pre applied yellow stuff that comes on S&S backing plate screws turns to powder upon installation.

My thoughts about the dry patch is the effect on friction when torqueing.  Now if you clean and reuse the fastener or upgrade it to grade 8 so it won't break, the torque with a wet drop of Loctite will be less?

The pin in the Twin Cam is a better idea. You can set the clearance as you please, and the pin just lifts out.

    There must have been a higher cost to machine the nest for the pin plus the bar stock than the grade 5 fastener and a piece of die cast plastic.  As we have seen, most of these changes are usually based on cost.  This one IMO has built in obsolescence for future repairs in the door.

[FSG]

   There must have been a higher cost to machine the nest for the pin plus the bar stock than the grade 5 fastener and a piece of die cast plastic.  As we have seen, most of these changes are usually based on cost.  This one IMO has built in obsolescence for future repairs in the door.

while S&S have come out with their cuff I'm surprised no one else has done anything,
I'm sure there could bee a drop in cuff that has a locating pin which would go in the bolt hole and the cuff held down by the lifter cover

[rigidthumper]

Cheap & functional are the hallmark of bean counters everywhere. I think that that failures of the plastic are uncommon, and it's easy enough to drop the lifters out the bottom if the cuffs are intact. Broken bolts (upon removal) seem to be more of an issue than actual broken cuffs.

[Deye76]

"Now if you clean and reuse the fastener or upgrade it to grade 8 so it won't break, the torque with a wet drop of Loctite will be less?"
Who said anything about torque? I didn't. So you're saying the problem with bolts breaking is torque?     I wonder if the patch turns to powder and the threads gall.

[Hossamania]

"Now if you clean and reuse the fastener or upgrade it to grade 8 so it won't break, the torque with a wet drop of Loctite will be less?"
Who said anything about torque? I didn't. So you're saying the problem with bolts breaking is torque? 

I think he is referring to the torque value needed being less with a wet lock as opposed to the dry lock, much like values change between a drop of oil under the bolt head as opposed to a dry bolt head. Not that the torque itself is breaking the bolt.

[kd]

"Now if you clean and reuse the fastener or upgrade it to grade 8 so it won't break, the torque with a wet drop of Loctite will be less?"
Who said anything about torque? I didn't. So you're saying the problem with bolts breaking is torque? 

I think he is referring to the torque value needed being less with a wet lock as opposed to the dry lock, much like values change between a drop of oil under the bolt head as opposed to a dry bolt head. Not that the torque itself is breaking the bolt.

Yes Hoss, that's most of it.  Deye, I also didn't say you did.    I will say clearly that I personally think the torque required to remove the fastener is more than the grade 5 quality can withstand.  (the reason is under discussion)  The existence of a problem is evident by the number of fractures reported here by folks in the business that do this regularly and encounter it almost daily.

The other part is, because it does have to go back together, what will it take to resolve this common issue ?  What will correct the weakness so it doesn't reoccur? The dry lock patch came into the conversation as possibly the reason some of this is happening. Should we blindly reinstall another identical fastener?  When the fastener is initially installed (or reinstalled) does the dry lock patch compromise the fastener by the way it increases the radial torque required to turn a fastener that is not rigid enough to be up to the task?       

It seems obvious (to me at least) that the grade 5 fastener is not up to the task at least when it comes time to remove it.  If it was, there wouldn't be all of these fractures.  On the other hand, with the demonstrated strength of the OEM lock patch, would an OEM grade 8 fastener not break but possibly pull or otherwise gall or damage the threads in the aluminum base beyond reuse simply because the obvious strength of the dry patch forces the failure to the next weak link?  Is the patch over the strength required?  The lifter cover as FSG said is holding the assembly in place anyway.  After all, the fastener (and cuff) is functionally just a positioning device. IMO there is an OEM engineering failure here and I expect there will be some sort of remedial change to address it in the future. 

I haven't seen any tools available to combat this problem when it happens.  There may be something out there but no one here has offered it up (yet).  For now, I consider it doesn't exist.  For the time being, I think the back yard garage solution that Hoss and his buddies came up with is an extraordinary resolution to removing the fastener shank when it does break and is at risk of being copied by someone for financial gain. Like that's never happened to any of our members before  .  (Hoss, it needs a smaller pilot hole for the starter bit.  That could be on the other side when the tool is flipped over.     ) IMO the aluminum block tool is at present a simple solution that anyone with access to a drill press and a gasket can make to attend to a known problem found in many thousands of already manufactured engines that will not benefit from any late to the party OEM design changes at the factory (if any). 

Thanks again for sharing it here first Hoss.

 

[Deye76]

Misunderstood KD, excellent explanation above. 

[To The Max]

Excellent discussion guys , i just had a thought. why not just fit a high quality stud in there and just lock tight a nut to hold down the cuff ? Max

[les]

Excellent discussion guys , i just had a thought. why not just fit a high quality stud in there and just lock tight a nut to hold down the cuff ? Max

Maybe just using a grade 8 bolt (like the S&S lifter cuffs do) of the exact same size might be easier. 

[Dan89flstc]

On the subject of the lifter cuff bolts...

When I put a socket on the bolt I do not use a back and forth motion as the bolt is coming out.  I only go counterclockwise. 

I agree with this method. I have had to remove a lot of very tight fasteners on jet engines, when I start turning them I keep going, no steps backwards.

It either comes out or breaks.

[les]

On the subject of the lifter cuff bolts...

When I put a socket on the bolt I do not use a back and forth motion as the bolt is coming out.  I only go counterclockwise. 

I agree with this method. I have had to remove a lot of very tight fasteners on jet engines, when I start turning them I keep going, no steps backwards.

It either comes out or breaks.

Thanks for the comment and your experience.  I'll keep doing it the way I'm doing it.  It's been successful so far.

[cbumdumb]

Maybe something at Harley changed but the last two M8's I have worked on the lifter cuff bolts came out easily .... I was sweating the thought of them breaking but was surprised that they weren't hard at all to remove both were 19's one feb build date the other I don't know.

[FLSTFIDave]

Maybe something at Harley changed but the last two M8's I have worked on the lifter cuff bolts came out easily .... I was sweating the thought of them breaking but was surprised that they weren't hard at all to remove both were 19's one feb build date the other I don't know.

My 2019 CVO, purchased in Dec 18 lifter cuff bolts were stupid tight.  We worried one would break.

[HogMike]

2019 cvo limited
Build date in Dec 2018
Bolts were very tight but a little heat got them out ok.

Not the first time I've noticed some bolts are harder to remove than others.
Could be a result of locking compound and procedure when torquing the bolts.

The engine plant has most of the assembled parts done by robots, but there are also some human interaction with jigs etc during the assembly.
I toured the engine plant in 1984 and again in 2013 and there's been quite a change!
I do think it is a much better and more reliable product today than in the past.
JMHO
 

[Admiral Akbar]

Once you get the cuff bolt out, do whatever you want. Blue works fine. Don't have to change the bolt is you haven't tweaked on it. The issue is that the patch sticks things up.  I've worked the bolt back and forth. That will loosen it up as the patch breaks down and the screw comes out.. This is different than say 18-8 stainless bolt and nut. The worst thing you can do in this situation is wiggle the nut back and forth. It will lock up.

Mike, you riding with Butch tomorrow?

[HogMike]

Once you get the cuff bolt out, do whatever you want. Blue works fine. Don't have to change the bolt is you haven't tweaked on it. The issue is that the patch sticks things up.  I've worked the bolt back and forth. That will loosen it up as the patch breaks down and the screw comes out.. This is different than say 18-8 stainless bolt and nut. The worst thing you can do in this situation is wiggle the nut back and forth. It will lock up.

Mike, you riding with Butch tomorrow?

Sorry, no.
Mother's Day and all that!

[Propflux01]

Bringing this up a few months.

I was considering replacing the cuff when doing a cam change later this season. I have been wondering if cuff replacement to the S&S is even an issue worth tackling for something like a woods 22x or an RS 468. If in fact, there is even a problem using the cuffs, or if there is even a 'failure rate' with them and aftermarket cams?

[les]

Bringing this up a few months.

I was considering replacing the cuff when doing a cam change later this season. I have been wondering if cuff replacement to the S&S is even an issue worth tackling for something like a woods 22x or an RS 468. If in fact, there is even a problem using the cuffs, or if there is even a 'failure rate' with them and aftermarket cams?

Understand your question and sorry I can't give failure rate data.  However, if you've ever held a stock cuff in your hand, common sense immediately tells you "this ain't it."  It also tells you that the stock cuffs could not possibly be made any cheaper (i.e. of lower quality and robustness).  It's about the lowest of the low.

[r0de_runr]

Maybe the synthetic cuff acts as a sound deadner??

[Oclaf]

Can't find the link, but there's a part that you can get that eliminates the cuff and eliminates the need to remove the bolt if you break it, if i broke one, that's the route i would go, much sturdier and all that jazz...i will look later...

[Propflux01]

Can't find the link, but there's a part that you can get that eliminates the cuff and eliminates the need to remove the bolt if you break it, if i broke one, that's the route i would go, much sturdier and all that jazz...i will look later...

Interesting.....

[Ohio HD]

I'm from Missouri, so I'd have to see how the cuff (either HD or S&S) can be eliminated. Their purpose is to keep the tappets from rotating in their bore. And without a bolt to hold "something" in a solid fixed location and centered over the lifter bore, how do you keep the tappets from rotating? 

[HogMike]

FWIW:
I like the idea of the S&S cuffs.
The fit over the lifters is pretty tight and on the install you can notice if they are aligned properly to allow the lifters to move easily without binding.

It is easier to remove lifters to check wear on cam lobes and rollers without going into the cam chest.

I'm thinking studs and nuts on the cuffs in the future.