Harmonic balancer/damper - How to remove and install
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| − | =Overview= | + | ==Overview== |
The harmonic balancer or damper is usually a tight press-fit onto the end, or "snout" of the crankshaft. This is so the torsional vibrations of the crankshaft generated by the power pulses of the engine can be transmitted to- and absorbed or dissipated by- the harmonic balancer. If the fit isn't tight, the harmonic balancer will not be able to absorb the vibrations and in some cases this can lead to a failure of the crank or damper key/keyway that locates the damper on the crankshaft in the correct position, or the retaining bolt could fail, not to mention possible internal engine damage resulting from the undamped harmonics. | The harmonic balancer or damper is usually a tight press-fit onto the end, or "snout" of the crankshaft. This is so the torsional vibrations of the crankshaft generated by the power pulses of the engine can be transmitted to- and absorbed or dissipated by- the harmonic balancer. If the fit isn't tight, the harmonic balancer will not be able to absorb the vibrations and in some cases this can lead to a failure of the crank or damper key/keyway that locates the damper on the crankshaft in the correct position, or the retaining bolt could fail, not to mention possible internal engine damage resulting from the undamped harmonics. | ||
| − | =Tools= | + | ==Tools== |
It is always advisable to use a dedicated removal tool for damper removal. To do otherwise risks damaging the damper beyond repair, damaging the crankshaft or other related parts and covers, or causing personal injury. Because of how tightly most dampers are pressed onto the crank, there's basically no way a damper should be able to be pried off anyway (one possible exception is the Pontiac V8, its damper is sometimes a tight hand fit, having a torque of 120 ft/lb for the 1/2-20 retaining bolt. Heat cannot be used because there could be damage to the damper oil seal. Also most dampers have an elastomeric band that separated the inner hub from the outer inertia ring. Heat can ruin the bond between the two, causing catastrophic failure of the damper that could damage the radiator, water pump, front mounted accessories, the hood, could possibly sever engine oil or ATF cooler lines, radiator hoses, etc. | It is always advisable to use a dedicated removal tool for damper removal. To do otherwise risks damaging the damper beyond repair, damaging the crankshaft or other related parts and covers, or causing personal injury. Because of how tightly most dampers are pressed onto the crank, there's basically no way a damper should be able to be pried off anyway (one possible exception is the Pontiac V8, its damper is sometimes a tight hand fit, having a torque of 120 ft/lb for the 1/2-20 retaining bolt. Heat cannot be used because there could be damage to the damper oil seal. Also most dampers have an elastomeric band that separated the inner hub from the outer inertia ring. Heat can ruin the bond between the two, causing catastrophic failure of the damper that could damage the radiator, water pump, front mounted accessories, the hood, could possibly sever engine oil or ATF cooler lines, radiator hoses, etc. | ||
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<br style="clear:both"/> | <br style="clear:both"/> | ||
| − | = | + | ==Crank bolt removal== |
| + | Many engines use a bolt to hold the damper on. In some cases like the Pontiac V8, the bolt torque is significant- 160 ft/lb. This means removing it with the engine in the vehicle can be difficult. On some engines just the engine compression and the friction from the belt-driven accessories will allow the bolt to be removed. | ||
| − | == | + | An impact wrench will almost always remove the crank bolt without needing to hold the engine from turning. But the room between the bolt and radiator seldom allows an impact wrench to be used. If you have a helper, they can use a lever to hold the flex/flywheel from turning. You can also run a pry bar or other similar prying tool through the puller bolts and wedge this tool against the vehicle frame, firewall, or ground to keep the crank from turning. |
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| + | An old trick for locking up the engine is to remove the plug from an easy-to-reach cylinder and bring it up to TDC on the compression stroke. Then turn the crank CW some more (past TDC), and using clothes line cord or similar, fill the cylinder up w/the cord. Rotate the engine CCW until it stops turning, then you can loosen the bolt. Reversing this procedure allows the bolt to be torqued- just be sure to remove/replace the cord after repositioning the crank/piston position so you're not bearing down on open valves. | ||
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| + | ==Damper/balancer removal== | ||
The pulley and anything else in the way is first removed so the damper can be accessed. | The pulley and anything else in the way is first removed so the damper can be accessed. | ||
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===With threaded damper bolt hole in crank=== | ===With threaded damper bolt hole in crank=== | ||
| + | If the crank snout is threaded, the use of a harmonic damper installer is possible. Simply follow the directions that come with the tool to install the damper, or see the instructions'''here'''. Use RTV in the crankshaft and damper keyway to keep oil from migrating through the key slot to the outside. Also be sure to grease the tool threads and the thrust washer to prevent galling. | ||
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| + | Torque the pulley and crankshaft bolts to spec. <br> | ||
| + | {{Note1}}'''[[Fastener torque]]''' has torque values for various engines. If your engine isn't covered, use the [http://www.derose.net/steve/resources/engtables/bolts.html '''appropriate table'''] to find the torque by the size/thread of the bolt. | ||
===Without threaded damper bolt hole in crank=== | ===Without threaded damper bolt hole in crank=== | ||
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There are a couple things that will help ease the job. | There are a couple things that will help ease the job. | ||
| − | *The damper is held on by a 0.0007"-0.0014" press fit. Heating the damper in 200º F hot water for | + | *The damper is held on by a 0.0007"-0.0014" press fit. Heating the damper in 200º F hot water for 15 minutes will cause it to expand a bit. Overheating the damper risks damaging the damper and/or the front seal. Chilling the crank snout with a bag of ice will shrink the crank a bit and is a much more effective and safer method of easing installation without a threaded crank. |
| − | *Use a sturdy block of wood like a 4-5" thick slice of a wooden fence post or 4x4 | + | *Use a sturdy block of wood like a 4-5" thick slice of a wooden fence post or 4x4- used grain-on, not across grain to help keep it from splitting- you'll be hitting it fairly hard in most cases, especially if no heat/cold is used. The wood is used to insulate the damper inner hub from the hammer blows. |
{{warning|NEVER hit the damper on the outer ring- this can break the bond between the rubber and steel, making the damper useless. NEVER hit the damper metal to metal with a hammer. A damaged damper could fail, possibly causing personal injury and damage to the vehicle or even bystanders. Use gloves and '''[[Health and safety in the shop or garage#Eye protection|eye protection]]''' at a minimum.}} | {{warning|NEVER hit the damper on the outer ring- this can break the bond between the rubber and steel, making the damper useless. NEVER hit the damper metal to metal with a hammer. A damaged damper could fail, possibly causing personal injury and damage to the vehicle or even bystanders. Use gloves and '''[[Health and safety in the shop or garage#Eye protection|eye protection]]''' at a minimum.}} | ||
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[[File:Sbc damper install non threaded crank.jpg]] <br style="clear:both"/> | [[File:Sbc damper install non threaded crank.jpg]] <br style="clear:both"/> | ||
| − | '''NOTE:''' The reference to threading capscrews to hold the hub and "flywheel" in place is for a 265 cid SBC that used a pulley and hub riveted to the flywheel. These were not actually dampers per se | + | |
| − | + | '''NOTE:''' The reference to threading capscrews to hold the hub and "flywheel" in place is for a 265 cid SBC that used a pulley and hub riveted to the flywheel. These were not actually dampers ''per se''; they contained no rubber or other means of absorbing/dissipating harmonics. | |
| − | == | + | |
| − | (This was previously a separate article by Techinspector1. | + | ==Harmonic damper install- honing to fit== |
| + | (NOTE: This was previously a separate article originated by Techinspector1, '''''Harmonic damper install'''''. The two articles were combined into this article.) | ||
The question arose the other day when someone suggested honing a damper hub in order to get it to press onto the crank snout of a SBC a little easier. Another contributor said there was no way he would hone a damper. The following is my reply: | The question arose the other day when someone suggested honing a damper hub in order to get it to press onto the crank snout of a SBC a little easier. Another contributor said there was no way he would hone a damper. The following is my reply: | ||
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Now, on your way home from having the machine shop hone the hub of your damper, stop by and pick up some dry ice. Once you get home, break up the dry ice into a one gallon baggie and wrap it loosely around the crank snout. Put the damper in a pan of water and bring it to a boil on the kitchen stove. Remove the pot from the stove and carry the whole thing to the garage. Remove the dry ice baggie from the crank snout. Spray the crank snout with WD40. With gloves on to prevent burning your hands, place the damper onto the end of the crank and engage your install tool. | Now, on your way home from having the machine shop hone the hub of your damper, stop by and pick up some dry ice. Once you get home, break up the dry ice into a one gallon baggie and wrap it loosely around the crank snout. Put the damper in a pan of water and bring it to a boil on the kitchen stove. Remove the pot from the stove and carry the whole thing to the garage. Remove the dry ice baggie from the crank snout. Spray the crank snout with WD40. With gloves on to prevent burning your hands, place the damper onto the end of the crank and engage your install tool. | ||
| + | [[File:Measuring points damper - keyway.jpg|thumb|550px|left|Measuring points of damper and crank snout]] | ||
| + | [[File:Crank snout - keyway dimensions.jpg|thumb|750px|left|Crank snout OD; damper ID; key/keyway dimensions]] <br style="clear:both"/>(NOTE: Two drawings immediately above from [[Media:General Damper Instr.pdf|Professional Products]]) | ||
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| + | ==References== | ||
| + | *[http://www.professional-products.com/PDF%20Instructions/General%20Damper%20Instructions.pdf Removal and installation info and specifics about various makes of engines] | ||
| − | + | [[Category:Good articles]] | |
[[Category:Engine]] | [[Category:Engine]] | ||
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