Messed up flywheel, any ideas?

SurfaRiver · 03-19-2005, 11:08 AM

So, I've been trying to convert my 79 stang into a manual for 8 months now. I got all the parts in the summer but couldnt do it because the "sellar" never mentioned that 2nd gear is shot. Then I went back to school where I couldnt do it. I got home for spring break and dropped the C4 and started bolting things up. Thats when I realized that 2/6 of the taps in the flywheel were completley stripped. I guess the "sellar" didnt realize that you only need to torque them down to less than 30 ftlbs.

Do you think I can drill out the holes another 16th bigger and put threads in em to save this $240 billet flywheel? Or did he sell me a worthless piece garbage & should I just go and throw it through his front window?

~Mark

~The Jester~ · 03-19-2005, 01:56 PM

If you only drill out the bad holes, the big expensive billet flywheel won't be balanced anymore. Drill them all, and you MIGHT be OK. Have to drill bigger holes in your pressure plate too (to fit the bigger bolts through it).

Personally I'd throw it through his window anyways, that sounds like more fun.

chatcher · 03-19-2005, 03:09 PM

i dont think id chance any type of failure in that area considering the potential cons jmo

SurfaRiver · 03-19-2005, 04:28 PM

do you mean dont try to drill em out because if it doesnt work it'll mess up the rest of the rest of the drivetrain or I might as well try it because otherwise its goign to the scrap heap?

chatcher · 03-19-2005, 04:49 PM

im no expert but i would guess that you could end up ruining more than just the flywheel by altering it unbalancing it as mentioned before could lead to failure of engine internals and or trans internals i just wouldnt take a chance with a part that im not completely comfortable with espc a flywheel id buy a stock replacment for now or save up and put a new one in i found a brand new sfi app billet fw on ebay a while back for $100 shipped its your call im just giving my op

rwhite65 · 03-20-2005, 01:47 AM

Or you can try and go by your local machine shop, show him what you got and see what he says. They can always try to fix it and check the balnace of it afterwards. Just my thoughts.
Ryan

andy669 · 03-20-2005, 08:38 AM

The factory bolts are a metric thread similiar to 5/16. I dont think a 3/8 bolt would fit very good in the pressure plate. Theres not a whole lot of room there and the head of a 3/8 bolt might be too big to tighten down properly.

Andy

SurfaRiver · 03-20-2005, 08:56 AM

well, we're gonna give it a go today. Looked at the bolt head size, it looks like if I use header bolts (smaller heads) it will clear the clutch just fine. I'll post in 12 hours or so and let ya know how it goes *fingers crossed*

Gearhead999 · 03-20-2005, 11:40 AM

I don't see why you couldn't drill them out and use Grade 8 bolts. If the head is a problem, how about socket head bolts [allen bolts]??

If you don't think you can do it, find a local machine shop. I wouldn't throw it away for that.

SurfaRiver · 03-21-2005, 08:44 PM

I did it, it worked like a charm

2 years planning
one bad deal
lots of repairs
working 5.0L mustang with 5 speed

Ieatcamaros · 03-21-2005, 09:47 PM

I got a hold of a flywheel in a similar situation once. The threads in a stock flywheel are 8mm x 1.25. Very similar to a 5/16-18 that Andy mentioned. The threads are not tapped very deep from the factory. You can go get a tap and tap the holes all the way through and get longer bolts. Just make sure the bolt doesn't stick very far out of the back of the flywheel. Works like a charm.

Glad you got her fixed, SurfaRiver.

03-19-2005, 11:08 AM	#1
SurfaRiver Registered Member Join Date: Mar 2002 Location: Ohio Posts: 54	Messed up flywheel, any ideas? So, I've been trying to convert my 79 stang into a manual for 8 months now. I got all the parts in the summer but couldnt do it because the "sellar" never mentioned that 2nd gear is shot. Then I went back to school where I couldnt do it. I got home for spring break and dropped the C4 and started bolting things up. Thats when I realized that 2/6 of the taps in the flywheel were completley stripped. I guess the "sellar" didnt realize that you only need to torque them down to less than 30 ftlbs. Do you think I can drill out the holes another 16th bigger and put threads in em to save this $240 billet flywheel? Or did he sell me a worthless piece garbage & should I just go and throw it through his front window? ~Mark __________________ 1979 Mustang ... 12K Holley 600 CFM 4 bbl Edlebrock Performer RPM Comp Cam 8.8 Rear end with posi from 88 stang Next Projects AFR Heads Stroker Crankshaft and new Pistons T5 Runs 15.0 now, need more traction Last edited by SurfaRiver; 03-19-2005 at 12:49 PM..

03-19-2005, 01:56 PM	#2
~The Jester~ Rat Killer Join Date: Aug 2002 Location: Cold ass Ohio Posts: 1,143	Re: Messed up flywheel, any ideas? If you only drill out the bad holes, the big expensive billet flywheel won't be balanced anymore. Drill them all, and you MIGHT be OK. Have to drill bigger holes in your pressure plate too (to fit the bigger bolts through it). Personally I'd throw it through his window anyways, that sounds like more fun. __________________ d-Con Racing "Nothing fancy, just 347 inches of RAT POISON!" MICE need not apply.....

03-19-2005, 03:09 PM	#3
chatcher Registered Member Join Date: Jun 2001 Location: butler pa Posts: 303	Re: Messed up flywheel, any ideas? i dont think id chance any type of failure in that area considering the potential cons jmo __________________ 92lx wannabe saleen

03-19-2005, 04:28 PM	#4
SurfaRiver Registered Member Join Date: Mar 2002 Location: Ohio Posts: 54	Re: Messed up flywheel, any ideas? do you mean dont try to drill em out because if it doesnt work it'll mess up the rest of the rest of the drivetrain or I might as well try it because otherwise its goign to the scrap heap? __________________ 1979 Mustang ... 12K Holley 600 CFM 4 bbl Edlebrock Performer RPM Comp Cam 8.8 Rear end with posi from 88 stang Next Projects AFR Heads Stroker Crankshaft and new Pistons T5 Runs 15.0 now, need more traction

03-19-2005, 04:49 PM	#5
chatcher Registered Member Join Date: Jun 2001 Location: butler pa Posts: 303	Re: Messed up flywheel, any ideas? im no expert but i would guess that you could end up ruining more than just the flywheel by altering it unbalancing it as mentioned before could lead to failure of engine internals and or trans internals i just wouldnt take a chance with a part that im not completely comfortable with espc a flywheel id buy a stock replacment for now or save up and put a new one in i found a brand new sfi app billet fw on ebay a while back for $100 shipped its your call im just giving my op __________________ 92lx wannabe saleen

03-20-2005, 01:47 AM	#6
rwhite65 Ride Hard Join Date: Oct 2000 Location: Wyoming IL Posts: 1,094	Re: Messed up flywheel, any ideas? Or you can try and go by your local machine shop, show him what you got and see what he says. They can always try to fix it and check the balnace of it afterwards. Just my thoughts. Ryan __________________ 65 Fastback 91 roller 306, H/C/I AOD-Bauman, PI Stallion, 4.10's and traction loc 04 Grand Cherokee Freedom Edition 79 Ford F-250 4x4 - Restored

03-20-2005, 08:38 AM	#7
andy669 Registered Member Join Date: Jan 2001 Location: Moline Il Posts: 901	Re: Messed up flywheel, any ideas? The factory bolts are a metric thread similiar to 5/16. I dont think a 3/8 bolt would fit very good in the pressure plate. Theres not a whole lot of room there and the head of a 3/8 bolt might be too big to tighten down properly. Andy __________________ 88 coupe 91 LX NMRA Pure Street 5120

03-20-2005, 08:56 AM	#8
SurfaRiver Registered Member Join Date: Mar 2002 Location: Ohio Posts: 54	Re: Messed up flywheel, any ideas? well, we're gonna give it a go today. Looked at the bolt head size, it looks like if I use header bolts (smaller heads) it will clear the clutch just fine. I'll post in 12 hours or so and let ya know how it goes fingers crossed __________________ 1979 Mustang ... 12K Holley 600 CFM 4 bbl Edlebrock Performer RPM Comp Cam 8.8 Rear end with posi from 88 stang Next Projects AFR Heads Stroker Crankshaft and new Pistons T5 Runs 15.0 now, need more traction

03-20-2005, 11:40 AM	#9
Gearhead999 Registered Member Join Date: Sep 1998 Location: Oviedo, FL Posts: 992	Re: Messed up flywheel, any ideas? I don't see why you couldn't drill them out and use Grade 8 bolts. If the head is a problem, how about socket head bolts [allen bolts]?? If you don't think you can do it, find a local machine shop. I wouldn't throw it away for that. __________________ "Support our Troops" Dave 1968 Cougar 2004 Thunderbird 2007 F150 Harley-Davidson, SuperCrew 1986 LTD 1997 Ranger 1992 Honda Civic

03-21-2005, 08:44 PM	#10
SurfaRiver Registered Member Join Date: Mar 2002 Location: Ohio Posts: 54	Re: Messed up flywheel, any ideas? I did it, it worked like a charm 2 years planning one bad deal lots of repairs working 5.0L mustang with 5 speed __________________ 1979 Mustang ... 12K Holley 600 CFM 4 bbl Edlebrock Performer RPM Comp Cam 8.8 Rear end with posi from 88 stang Next Projects AFR Heads Stroker Crankshaft and new Pistons T5 Runs 15.0 now, need more traction

03-21-2005, 09:47 PM	#11
Ieatcamaros Domestic Rice really sucks! Join Date: Apr 2002 Location: KY Posts: 973	Re: Messed up flywheel, any ideas? I got a hold of a flywheel in a similar situation once. The threads in a stock flywheel are 8mm x 1.25. Very similar to a 5/16-18 that Andy mentioned. The threads are not tapped very deep from the factory. You can go get a tap and tap the holes all the way through and get longer bolts. Just make sure the bolt doesn't stick very far out of the back of the flywheel. Works like a charm. Glad you got her fixed, SurfaRiver. __________________ The sig says it all.

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