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Advice for removing Flywheel

D

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New member
Hi,

I have to remove the flywheel from my 88spl (1989) and need some advice on how much torque I can put on the "harmonic balancer puller" I am using to lift it off. I believe I have the correct bolts to attach it to the flywheel (hardened 5/15-24). I have it tightened to the point where I worry that the three bolts might strip out.

I do have a torque wrench. Would anyone know how many ft-lbs I can put on the central, lifting, bolt before I need to worry?

Are there any tricks that might help? I did try to tap upwards on the underside of the flywheel but did not hit it too hard.


Thanks for your help
 
Do not hit the underside of the flywheel!--------With the 3 puller bolts tight, you need to give the center bolt on the puller a good bump with a hammer and it will pop off.
 
Caution..........Hitting down on that setup can damage the crankshaft bearings ..........

I always have always first run a bolt thru each hole thread length to be sure the bolts are free to screw all the way in if needed. I then LUBRICATE the bolt threads with wheel bearing grease to make sure all the twisting force is being used to lift the flywheel.

Most important......Is the increasing the twisting force ......equally on all the bolts. I tap each of the bolt heads lightly as they get really tight.

Sometimes I bring a torch to quickly heat the flywheel about 2 " away fro the shaft. I wrap the shaft with a water soaked rag. It does not touch the flywheel.

Yes. I have ruined a flywheel on a really tight one..............Out comes the drill & small cutoff wheels.

My attitude is........... SCREW the flywheel..............DO NOT damage any other part of the engine.
 
Thank you both for your replies.

Re bumping the center bolt: any hitting I do would be gentle enough to not cause damage, but which direction would that be, down or at a 90% angle to the bolt?

In regards to heating the flywheel: does it have to be with a torch or could I use a heat gun (or even hot water assuming it were possible to shroud the rest of the engine underneath it from getting wet)?
 
Duncan

When you asked about the direction to hit the cranshaft bolt.

Most all of us would want you to NOT try to take apart the flywheel from the end of the crank shaft.

Have a machanic do it.................Never hit any bolt or nut side ways............To great a chance of damage to the parts.
 
Thanks - guess my questions display my level of nubieness so your concern is on target and is appreciated. Still, I would like to persevere with this task so now have another question: with the puller still tightened I have used a heat gun to heat up the flywheel (Goldilocks hot) and a can of compressed air to cool the threaded top of the crankshaft (most of the can - shaft would hold a white/frozen color for 3-4 seconds then go back to it's normal/steel color) . I hit down on the lifting bolt once the cooled threads did not have the frozen look (halfheartedly, holding the hammer halfway up the handle). Still no go. I put penetrating oil back on it (removed it before using the heat gun) and will try again later.

Are there any concerns with the above process? Does a heat-gun perform as well as a torch for this? Can't see why not but then again I have not seen anyone mention using one. Not too keen on using a torch. If it is necessary, then I guess I will use a mechanic.

Thanks in advance for your help.
 
You can do what you want, but I have removed many, many stuck flywheels. Put a very hefty puller on it, no toy, install the three bolts, tighten down on the center puller bolt. Now, how tight, you ask. I have used an air impact gun to tighten it, and the three puller bolts have actually bent and distorted. so that is how tight. Then, take a big hammer and smack the crap out of the center puller bolt. It should pop right off. If it doesn't, then the job may need a mech that has done it before....I never, ever had to destroy a flywheel to get it off, nor have I damaged any bearings by hitting the center bolt. I hit them pretty hard, too. Here is a pic of the type of puller I use: http://www.offshoremarineparts.com/781/prod_8713.html. It has to be hefty. Goldilocks hot? HAH...if you use heat, get it Papa Bear hot.
 
Actually there is a concern with heating up the crankshaft end. Some times, Depending on crank metal, the super hard strength of the crank keyway & nut threads can be severely weakened. Russian Roulette.

The heat is to expand the flywheel hole a little, while NOT expanding the crankshaft diameter at all. That combination gives it the POP off.
 
A side note. My puller has never bent a puller bolt. They are Like Titanium. So are the rest of the parts. I usually leve a nut & washer on the threads loosely. Had one pop so violently that it fell to the floor. Nut & washer ever since.

Old DIY motors have submersions. Then the taper fit REALLY locks up tight.
 
Thanks everyone for your suggestions. Given there is some differing views on using too much heat I will first focus on the pulling force, but I have one more concern to allay first. I do have a torque wrench (well, I do now that I bought it to remove the big nut holding on the flywheel (as if it really needs it... ;) but I am pretty sure that left unchecked I could do the following damage with it: pull out or snap off one or more of the three case hardened bolts. If one does get pulled out I believe I could re-tap the hole for a different sized bolt. Is that right? On the other hand if one snaps then I have wrecked the flywheel and will need a new one as well as the mechanic I should have called originally, or is there a DIY way out of even this situation?
 
All torque wrenches I have ever used are for SPECIFIED TIGHTENING in 1 direction only. Use a non-torque wrench for any gear puller work.
 
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