RE: Crank Pulley removal
 

I got mine off about two weeks ago with a breaker bar w/ an impact socket and a chain wrench holding the pulley.

RE: Crank Pulley removal
 

Here's the very recentexperience of an automotive technician in exactly the same situation:
https://www.hondaaccordforum.com/m_89849/tm.htm

RE: Crank Pulley removal
 

i don't know why everyone has problems with the crank bolt - it's only 181lb ft. i can get it off using my snap on impact(xt7100 - http://buy1.snapon.com/catalog/item....mp;dir=catalog)


if it can't break it loose i break it loose with my 24" breaker bar and that's with the front mount already loose. you need to use a crank holding tool( http://cgi.ebay.com/ebaymotors/Honda...spagenameZWDVW) though. that's a must.

RE: Crank Pulley removal
 

Yes, it was torqued to 181 ft. lb., but most of our crank bolts have not been removed that often and have probably seized. Most of us don't have 700 ft. lb. impacts either.

RE: Crank Pulley removal
 

It's uncertain what causes the dramatic increase in removal torque compared to installation torque. I've heard speculation that engine impulses to the crankshaft from cylinder combustion pressure is causing the bolt to tighten. Hard to believe, but still something causes this torque increase. My theory is the bolt is lubricated on installation and lubricant evaporates or carbonizes, leaving much higher bolt/thread friction to overcome.

Some have had results w/ a 500+ impact wrench w/ long (several minutes) continuous impacting to finally release. A good air compressor and hose are also essential components of air impacting. You have to get the adequate air delivery at high pressure to get maximum impact torque.

good luck

RE: Crank Pulley removal
 

several minutes? ouch...even if my gun was 500ft lbi wouldn't push it like that. if i don't break it loose after 2 or 3 trys(continuous impact operation lasting 5 seconds or so) i break out the breaker bar! save the impact! use some muscle! hehe

i just modified a fitting for my air hose - it changes the diameter of the nipple so i get more volume of air at 150psi, it hasn't failed since i did that. i have that nipple on it's own dedicated hose and only use it for crank bolts.

using the 24" breaker bar is very easy to break it loose when the car is 8 ft in the air. you get a lot more leverage and power.

most crank pulleys are on the crank up until timing belt(usually 7 years). it :( )

RE: Crank Pulley removal
 

Belowis an interesting thread about impact wrenches and sometheories about why crank bolts mightover time becomeso difficult to remove:
https://www.hondaaccordforum.com/m_23717/tm.htm

RE: Crank Pulley removal
 

Tony1m, thanks for the thread lead. I agree that the vibration and shock of an air or electric impact tool has a beneficial effect, allowing removal w/ reduced torque. However, that does not explain how the bolt gets so tight in the first place.

One other theory is the large permanent washer at the base of the bolt is slightly frozen (corrosion) to the crankshaft pulley. This would exert much larger torque resistance than the bolt alone due to larger diameter of the washer. However, if this was the source of the problem, then penetrating oil, heat, etc should work like a charm and this doesn't seem to be the case.

BTW, heat may not be beneficial as you are expanding the bolt itself and increasing it's diameter slightly, probably much more than the crankshaft threaded hole enlarges (much larger mass = much larger thermal inertia). If you could somehow chill the bolt w/ liquid nitrogen spray, this might help, however the cold may reduce the toughness of the bolt, and could lead to bolt failure,... a real bummer.

I will perform a few calcs on the bolt to see how much torque load the bolt should be able to resist before yielding. The bolt is high-strength, and obviously very tough since I've read of no one whose managed to twist one off despite some apparently enormous torques.

Regards

RE: Crank Pulley removal
 

I could find no information on the crankshaft pulley bolt's actual yield strength, but the highest strength metric bolt grade I found was 1200 MPa (~175000 lb/sq-in). This results in a torsion yield capacity of about 1200 ft-lbs. Tony1M's concern about bolt failure could be a valid. Certainly It appears that folks are putting torques up near that value on the bolt.

However, the absence of any failures suggest the bolt strength margin is adequate in any case.

regards