Do you have to install all flywheel bolts?

[Cdc1221]

Leaving a bolt out of a flywheel is the same thing as putting a wrong harmonic balancer on a crank. Throws it out of balance and it starts wearing bearings out. Assuming that it would even be driven, because the vibrations would rattle your teeth out

 

[WickedQuikAWD]

^ You "can" do just about anything, but it is half assing it, and will lead to destruction later down the road (if it last's that long)

Listen to the sound advice above, the man speaks the truth. You will very likely have some serious engine/trans bell housing damage occur from running your car without all of the flywheel bolts installed. If you do go this route (and please, for the sake of your wallet, saftey, and our entire communities desire not to see another DSM on the side of the road or on a rollback...Don't) it should only be for a short time while waiting for parts with very conservative driving on stock boost levels and no revving past 4k rpm.

I personally would use timeserts instead of traditional helicoils. You can find them at timesert.com and the description should tell you why they are far superior in quality when used on a high stress component. In a perfect world, you would simply replace the crank... But the timesert is your next best option. I have used them with great success in my machine shop and have torqued them to well over 100 ft/lbs without issue. If you have any questions about timesert application you can call them at 800 423 4070 Monday through Friday 6am to 4pm PST.

Now you asked why it is a bad idea. Several people said it would cause an imbalance in the crank due to the missing weight... This is very true. The flywheel bolts have a significant weight to them... About 34 grams if I am not mistaken. Given that rotating assemblies are balanced to the gram... A 34 gram imbalance could prove to be seriously significant. Now think about that crank spinning at stock redline of 7500 revolutions per minute (125 times a second) and you can imagine how things would get out of hand quickly. If you don't believe me, take a piece of gum or modeling clay that weighs 34 grams and stick it to the blade of a fan and turn it on at high speed. It is a crude comparison, but you will see the vibration caused prior to the added weight flying off.

Now another thing to consider is the forces imparted on the flywheel itself. Much like when you are torqing down a head... The bolts are torqued in a specific order and in steps to prevent warping. The same goes for your fly wheel. When you torque down all the bolts except one, there is a chance that you will warp the flywheel to some extent or fatigue the metal in that area. Add in the pressure from the clutch and the torque that the flywheel experiences trying to put the power to the ground and you can imagine how a missing bolt would be detrimental to the flywheels longevity. Those are just a few reasons, but in my experience... Having a missing bolt is never a good thing. Be careful, and if you do decide to run the the car missing a flywheel bolt, take it easy... Listen and feel for vibration and odd sounds (as they might be your only advance warning prior to catastrophic failure) and buy yourself a Scatter Shield!! You don't want to be on the mean end of a flywheel/clutch grenading through the transmission bell housing. Good luck and feel free to PM me if you have further questions. Please post your results/findings, as that is the only other DSMers can learn from your experience. Good luck.


~Seth

 

[Iyaoyas]

Dont assume I'm going to Mickey mouse my crank. I'm simply asking WHY...
Chevy guy I know keeps saying just bolt it up and I want some stable proof as to why you can't just go doing shit like that to these cars or any car for that matter.

I guess you can say i am one of those chevy guys. I run a Dirt track late model race car with a 625HP chevy 350. I have in a pinch ran with a missing flywheel bolt for a few races. I only have to race about 20-30 laps turning about 8k RPMs That being said i would not suggest doing that. I know that i did not really have any vibrations, that is what your harmonic balancer AKA: vibration damper is for. I am still kinda new to making these kind of cars go fast, so it might mater. But i have had to do it on 2 different occations and never had anything break on me, but that could have been luck. Bottom line is I would recomend getting it fix correctly, but if it your only way to get to work/school sometimes you have to do what you have to do

 

[-red97rum-]

Go for it. And launch the piss outta that thing

I wouldn't do it man. I seriously couldn't do that to my car, I couldn't drive it knowing I half assed something like that. Do it right, so you don't have to worry about it.

 

[TSITurbo95]

Listen to the sound advice above, the man speaks the truth. You will very likely have some serious engine/trans bell housing damage occur from running your car without all of the flywheel bolts installed. If you do go this route (and please, for the sake of your wallet, saftey, and our entire communities desire not to see another DSM on the side of the road or on a rollback...Don't) it should only be for a short time while waiting for parts with very conservative driving on stock boost levels and no revving past 4k rpm.

I personally would use timeserts instead of traditional helicoils. You can find them at timesert.com and the description should tell you why they are far superior in quality when used on a high stress component. In a perfect world, you would simply replace the crank... But the timesert is your next best option. I have used them with great success in my machine shop and have torqued them to well over 100 ft/lbs without issue. If you have any questions about timesert application you can call them at 800 423 4070 Monday through Friday 6am to 4pm PST.

Now you asked why it is a bad idea. Several people said it would cause an imbalance in the crank due to the missing weight... This is very true. The flywheel bolts have a significant weight to them... About 34 grams if I am not mistaken. Given that rotating assemblies are balanced to the gram... A 34 gram imbalance could prove to be seriously significant. Now think about that crank spinning at stock redline of 7500 revolutions per minute (125 times a second) and you can imagine how things would get out of hand quickly. If you don't believe me, take a piece of gum or modeling clay that weighs 34 grams and stick it to the blade of a fan and turn it on at high speed. It is a crude comparison, but you will see the vibration caused prior to the added weight flying off.

Now another thing to consider is the forces imparted on the flywheel itself. Much like when you are torqing down a head... The bolts are torqued in a specific order and in steps to prevent warping. The same goes for your fly wheel. When you torque down all the bolts except one, there is a chance that you will warp the flywheel to some extent or fatigue the metal in that area. Add in the pressure from the clutch and the torque that the flywheel experiences trying to put the power to the ground and you can imagine how a missing bolt would be detrimental to the flywheels longevity. Those are just a few reasons, but in my experience... Having a missing bolt is never a good thing. Be careful, and if you do decide to run the the car missing a flywheel bolt, take it easy... Listen and feel for vibration and odd sounds (as they might be your only advance warning prior to catastrophic failure) and buy yourself a Scatter Shield!! You don't want to be on the mean end of a flywheel/clutch grenading through the transmission bell housing. Good luck and feel free to PM me if you have further questions. Please post your results/findings, as that is the only other DSMers can learn from your experience. Good luck.


~Seth

 

[greekgodchaos]

Me personally I wouldn't go without it. I've been on 3 wheels studs on 4 lugs and 4 studs on 5 lugs. No noticeable difference...

Lady luck must like you then, I was on 4 studs forever, then one broke, then another broke, then the last 2 broke...while I was doing 40mph. Luckily I skidded into an empty parking lot that was right off the road, only to watch in shock as my wheel rolled away from me into the dark of the night...

Bottom line is this; would you be willing to risk more damage later that will cost you even more $$$ in leu of being lazy and NOT fixing the problem that can prevent all that agony later down the road? The choice is up to you.

 

[jrohner]

The amount of time spent on this thread could've been spent tapping or helicoiling it and fixing it. It's easy and doesn't take very long.

 

[awzer2]

The amount of time spent on this thread could've been spent tapping or helicoiling it and fixing it. It's easy and doesn't take very long.

Yeah just fixed it right now.. Just have to put it all back together now ...Do I have to torque the bolts with a torque wrench or do I just do it to where I cant turn it anymore.. In other words does it need to be exactly the amount specified to torque?

 

[Alex7747]

Yeah just fixed it right now.. Just have to put it all back together now ...Do I have to torque the bolts with a torque wrench or do I just do it to where I cant turn it anymore.. In other words does it need to be exactly the amount specified to torque?

there is a reason there are torque specs... yes you should torque them to the correct amount

 

[mattasi]

Yeah just fixed it right now.. Just have to put it all back together now ...Do I have to torque the bolts with a torque wrench or do I just do it to where I cant turn it anymore.. In other words does it need to be exactly the amount specified to torque?

Man you just don't want to do this job properly do ya..

Yes exactly torque to 100 ft-lbs, in a pattern simular to your lug nuts.

 

[awzer2]

Man you just don't want to do this job properly do ya..

Yes exactly torque to 100 ft-lbs, in a pattern simular to your lug nuts.

I just like to trip ppl out I have a t wrench

yeahhhhhh!!! today i fixed my threads. then installed my new oem flywheel bolts purchased from tim zim tmzperformance,applied locktite ,torqued to 95-100 lbs .
then installed the new TO bearing,
and finally moved on to my pressure plate and clutch.
now with the PP i had some trouble..
i torqued one of the bolts down and it would not click !
i kept turning it then SNAP!
damn thing broke.
so i immediately got a pin and hammer to make a dent on the broken bolt shaft to prep for drilling and tap to back it out.
successfully removed it then went back to work.
i tightened down the P plate bolts in a circle pattern till the lil' plate lips kissed the flywheel, and viola they finally torqued according to my wrench at 14 lbs. which was specified.
im not sure if that was the correct way so correct me if im wrong..
anyways tomorrow im finally re installing the transmission and hopefully all is well.
this nightmare i had started out with a warped fidanza flywheel. incorrect bolts.
and zero loctite. which caused my flywheel bolts to strip my crank holes... WHEW hopefully you guys understand my explanation.

 

[WickedQuikAWD]

Sounds like you are on the right track. Just for future reference, you should tighten bolts in a "star" pattern, not a circular one. Basically you tighten bolts that are opposite each other, farthest possible away from the last bolt you torqued. It sounds like you are already step torquing the bolts (good job) but just in case anyone else doesn't know, you should run bolts in by hand until they bottom (if you can't spin a bolt in easily with your fingers the threads are damaged or there is something obstructing the bolt) to prevent cross threading and then using the star pattern... Torque in steps. Three steps should be more than sufficient. Just devide the specified torque rating in thirds and proceed accordingly. For instance, if the factory torque setting was 90ft/lbs... Spin the bolts in finger tight, then torque all the bolts in a star pattern to 30ft/lbs, then 60, and finally 90. Be sure after you torque to the final setting that you recheck each bolt with the torque wrench to ensure the first few bolts tightened didn't loosen up when the others fully seated. I personally am a big fan of buying several paint markers and marking each bolt after it has been torqued properly so I have a visual indicator that the work has been done properly. The next time I work on the car, I either remove the previous marks using brake clean or use a different color paint pen. This prevents forgetting to tighten one bolt, as we all get forgetful at times. I would also invest in a good metric tap and die set to chase all threads prior to assembly to ensure your car stays happy and goes together/comes apart easily. Copper anti seize is also awesome to prevent heat/rust welded or galled bolts from being hard to remove or snapping off. Good luck, and feel free to PM me with questions anytime.

PS: I would buy both a Chiltons and Haynes manual, and the factory manual as well. Factory is best, and I'd put Chiltons in front of Haynes any day... But having all three to reference each other against is the best possible option.