Arp flywheel bolt snapped :(

mytmk3

Member
Oct 16, 2007
643
2
18
christchurch
Sooooo there's a bit of back story to this will get to later when I'm not using my phone but

I have 2 arp flywheel bolts snap on me today one broke off at the head and the other half way down the threads and will need the power of Thor to get them out dan tight!

So I understand these are ment to be stronger bolts will it be harder/need some special drill bit to get these out relatively unhappy at the moment

Any insight apreciated
 

mytmk3

Member
Oct 16, 2007
643
2
18
christchurch
they snapped trying to take them out

right heres the long story

I had just bought an os triple plate clutch and r154 to swap out my w58 and I bought arp flywheel bolts at the same time

the os flywheel was a very tight fit on the crank so I lightly tapped it on with a with the rubber end of my hammer then using locktite and a torque wrench tightened them up to the listed specs(cant remeber off the top of my head)

all looked got tried to wiggle the flywheel to make sure was on fully didnt move so put in clutch and box then having dramas seting up the cluch sent it to a shop they got the clutch movement right but it had a horrible rattle at idle

now I got mixed reviews on thye noise (its hard to diagnose something over a youtube vid but even in person some people said they had herd multiplate clutches sound like that that were fine otheres said na somethings fucked)

the rear main was leaking so I decided to pull the box to replace that when I got the box off the flywheel had some movement(the rattling noise at idle )

so im guessing the flywheel didnt move when i first put it on because it was just a really tight fit and the arps were getting torqued against the end of the threads not the flywheel on my back in the dark I unfortunaly didnt notice this

I measureed the arps against the old flywheel bolts I was using and they are 2mm longer .

so im thinking I either got the wrong ones or the os genkin flywheel is thinner where it bolts on

either way I have two broken arp bolts stuck in my motor I practiced drilling on of the broken ones in the vice my cheap shit drill bits arent going to cut it that doesnt overly surprise me

the real bitch is that one of them is broken half way down the threads :(
 

hvyman

Dang Dude! No Way Man.
Staff member
Apr 17, 2007
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Fullerton,CA
I would get a good bit. Drill in the center of it and then get a easy out. Use lots of pb blaster. and hope it will come out easy.

IF thats a no then need a slightly bigger bit.
 

suprarich

Guest
Nov 9, 2005
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ohio
they are longer, you need to use washers on them sometimes to prevent the bolt from bottoming out. If the bolt hits bottom, it will gall the threads of the crank. A carbide drill will work on the arp. They are 8700 series chrome moly heat treated, so pretty hard.
 

CT26smoker

Banned
May 25, 2010
223
0
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Houston
I had to bottom tap the holes in my crank.
The ARPs were not bottoming out, but the threads in the crank were not tapped all the way to the bottom of the hole.
A $10 tap fixed that.

If you torqued them into the partially tapped threads at the bottom of the hole, then you have a hell of a job ahead of you.
Another thing, Loc-Tite releases with heat.
I have removed broken bolts that had thread locker on them by heating the center of them with a small tip on an acetylene torch for just a few seconds.
But I am afraid that the thread locker is not the problem, but most likely the interfearance fit of the bolt being forced into the partial threads at the bottom of the hole.

Good luck.
 

adampecush

Regular Supramaniac
May 11, 2006
2,118
3
38
Edmonton
Did you modify your torque setting to include the loc-tite on the bolts?

Specified torque is a function of thread condition (e.g. lubricated, dry, etc). A dry torque setting used on loc-tite covered threads would likely exceed the intended preload on the bolts, potentially contributing to the failure.
 

airhead04

New Member
Aug 21, 2009
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Lima, Ohio, United States
Had a similar problem. What I did was get a propane torch, a drill bit like what suprarich told you about, and pb blaster. The Heat (not excessive heat) should help with removal of the broken arp.

Another question, what color loc tight did you use? was it blue, red, or purple?
 

mytmk3

Member
Oct 16, 2007
643
2
18
christchurch
I torqued them to 63 with red/262 loctite it did feel realy tight should have knowen something was up it was my fault I guess some times we learn the hard way
 

mytmk3

Member
Oct 16, 2007
643
2
18
christchurch
http://www.supramania.com/forums/sh...lywheel-bolts&highlight=flywheel+bolts+torque

thats what I followed maybe rattling was the wrong word knocking when you would put your foot on the clutch the knocking stoped and did the normal multi plate rattle

the flywheel had atleast 2mm of freeplay to wobble back and forth "knock" made the noise turning over by hand with the box off still removed flywheel noise stopped presumably the realse bearing was holding the flywheel on flat when my foot was on the clutch so no noise and higher rpm centrafugal forces or loud ass turbo hid the noise.

gotta go find some tools now

cheers

side note seen as the 4age kit came with 2 spares and I only broke 2 bolts would it be safe to reuse the ones that didnt break and my spares with washers or just get a new set??

cheers scott
 

boostcraver

Member
Mar 13, 2010
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Louisville, KY
mytmk3;1707404 said:
side note seen as the 4age kit came with 2 spares and I only broke 2 bolts would it be safe to reuse the ones that didnt break and my spares with washers or just get a new set??

Considering all the forces exerted on the pressure plate and clutch in a high horsepower car, I would go with new ones, but that's just me. I have no factual reason for that recommendation, just would do it for a little extra peace of mind. It all comes down to one simple question: How many times do you want to pull the trans, drill out the broken bolts, fix what the loose flywheel/clutch tore up, reinstall the trans, etc.?
 

IBoughtASupra

New Member
Mar 10, 2009
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Queens, NY
Just get new ones, they are cheaper. ARP head studs can be reused but I don't. I believe Ian said he changes the nuts on the studs every six or seven times. I am not sure exactly, but I believe it was him who said that. ARP flywheel bolts are cheap so you might as well get new ones.