Crankshaft pulley bolt blues

[cmittle]

Before buying another impact be sure to check it's required CFM to meet that 1000 ft-lb rating. It would not surprise me to see it say something like 15 CFM. I'd be willing to bet that the IR impact puts out nearly an equal amount of torque at the same CFM (max of your current compressor) as the other.

Sounds like you've got some more help on the way though. Hope you get it and most importantly, be careful!

[Twerp]

Somebody once told me that it's PSI that makes the real difference with impacts. If that is the case, I was able to get some decent pressure. I just might not be able to sustain the harder blows for long. So with shorter bursts, it might work... maybe... Then again, I'm pretty new to air tools. I guess we'll see what happens with the special tool that I ordered. The situation is starting to get desperate though. I need to vacate the garage soon.

[TestDrive]

Originally Posted by Twerp

Somebody once told me that it's PSI that makes the real difference with impacts. If that is the case, I was able to get some decent pressure. I just might not be able to sustain the harder blows for long. So with shorter bursts, it might work... maybe...

PSI, CFM, tool design and manufacturing tolerances are all very important.

Typically a 1/2 pneumatic impact will have 2 to 8 vanes or hammers.
In general more vanes means more more blows per minute and greater delivered foot/lbs torque for any given PSI.

Turning up the compressor's cut off pressure will help regardless of your particular pneumatic impact gun.
But no matter how much you may wish and no matter what you've been told, it's not going to turn a
$35 2 vane / 2 Hammer Central Pneumatic
into a
$290 7 vane / 7 hammer Ingersoll-Rand

The 7 vane gun connected by an adequate ID hose to an adequate volume tank pressured to 90 psi will deliver more foot/lbs of torque than a 2 vane gun using the same hose connected to the same tank pressured to 120 psi.

For purposes of exposition, here are the specs for the second gun with my comments in red.

• 7-vane motor 3.5 times more vanes than 2; probably not much more than 2 times the torque
• Torque range: 50-600 ft. lbs Better tools have greater range and finer control.
• Max. torque: 625 ft. lbs. (fwd) Torque of each clockwise hammer blow.
• 700 ft. lbs. (rev) Torque of each counter clockwise hammer blow.

  More umpf loosening than tightening! Not always true for cheaper tools.

• Nut-busting torque: 1000 ft. lbs Maximum 6 seconds cumulative - see below.
• Impact: 1250 BPM Blows per minute under load.
• Free speed: 9500 RPM
• Standard bolt capacity: 9/16' Shaft size not head size
• Average air consumption: 5 CFM (24 CFM under load) Under load CFM is the important number.
• 1/2'' anvil
• Tool weight: 3.95 lbs. A lighter tool of equal torque will cost more.

From the main body of the advertisement - "Can loosen a nut tightened to 1000 ft. lbs. in 6 seconds" Six seconds is 1/10 of a minute. The gun delivers 1250 hammer blows per minute, so this is an estimation of the cumulative effect (static torque) of 125 hammer blows each delivered at 700 ft. lbs. of torque.

Let's talk about air hose for a moment. Though, the inlet of most any 1/2 pneumatic impact is going to be 1/4" NPT, it is very, very, very important to connect it to the compressor tank using at least 3/8" air line.

1/2" air line is better yet and is almost required if the hose is very long more than 25 feet.

When you hook a pneumatic tool up to the compressor tank and use it, air is depleted from the tank. When the pressure drops below a preset level (say 80 PSI - LESS THAN MOST ANY IMPACT GUNS RATED PSI ) the compressor kicks on and attempt to replenish the depleted reservoir. If the compressor and tank are adequate and you're just doing run of the mill work - you just continue on and the compressor eventually catches up. However if you're working on seriously stubborn nuts/bolts - looking for maximum torque, it's time to stop using the tool and wait until the compressor kicks back off. Then with a full reservoir tank at maximum PSI, you can try again.

The bigger the compressor tank the longer your tool will operate near it's maximum torque. Again you need adequate size hose running from the tank to the tool.

HOW TO SQUEEZE EVERY LAST BIT OF TORQUE FROM YOUR EXISTING PNEUMATIC TOOLS

1. Be sure you compressor is turned up to it's maximum rated PSI, but not more than the maximum rated PSI of any reservoir tank. (SAFETY FIRST)
2. Use you shortest, largest ID hose to connect the tool to the reservoir tank.
3. Deplete enough air from the reservoir to force the compressor to cycle on and wait for the charge cycle to complete.
4. Squirt 1/8 to 1/4 teaspoon of pneumatic tool oil directly in to the input port of your disconnected pneumatic impact tool and reconnect. This squirt of oil will briefly (1 second or less) boost the tools effective torque at it's next use. Oil will spray out the exhaust ports of the tool. If 1/4 teaspoon of spaying oil is going to be a problem, wrap the tool in a shop rag prior to use.
5. Operate the tool in a 3-6 second attempt to loosen the stubborn fastener.
6. If your reservoir tank is still with in a PSI or two of maximum, repeat steps 4 through 5. If your reservoir tank is too far below maximum PSI, repeat steps 3 through 5. If the fastener hasn't come loose after 20-30 repeats, sorry, you need better equipment.

If you need better equipment, replace sub-par hose first.
If you can borrow a better impact tool, do so.
If you have a tiny reservoir tank and you tool's rated CFM is high, try adding an auxiliary reservoir - even if the new auxiliary tank will require a slight lowering of maximum PSI. (See step 1 above).

If you have to buy a more powerful impact gun, keep your old one. Only use the newer, better tool on stubborn fasteners. Performance degrades - they only hold up so long.

[2000mc]

Originally Posted by Twerp

I borrowed an IR 600lb impact from a guy that I work with and that didn't do it.

if that didnt do it, i'd be more concerned about breaking off the head, and leaving the rest of the bolt in the crank. guess i'm not quite sure if the car has been disabled until the pulley is replaced, but if not, stop. if it has been, putting money into impact vs. going to a mechanic, may not work out finincially if you have to take it in to get the bolt drilled out.

i have a IR 2135qti, compared to the older IR composite guns (600lb) its lighter and faster, but it probly wouldnt be more helpful in your case. if a older one cant budge it, 95% of the time a newer one wont, or it will take the head off. or if you must anyway, the new 2135timax has 780lbs in rev. and 1100 nut bustin

[Twerp]

Actually, I managed to get the damn bolt out. I went ahead and ordered that special tool that holds the pulley. I found it for less than $10. Can you believe that there are places that sell the same thing for near $80? I also got a 24in breaker bar for about $10.

I connected the special tool to my old breaker bar and rested that on the garage floor with the other end connected to the crank pulley. I hooked up a beefy socket to a beefy extension to my new beefy breaker bar. I had a cinder block and some patio pavers supporting the extension so that it was just pure torque going to that bolt. I bounced on the breaker bar a couple times and then added a foot and a half long pipe to the back of the breaker bar. I had about three feet of leverage at that point. After pressing on that for a while, I eventually got up and stood on the thing. A couple of bounces from my 190lb heft broke that bolt loose.

Yeah, when I suddenly came crashing to the floor, I thought I had broken something else, but after checking the special tool, the extension, the socket and all, I determined that everything was fine. I flipped the breaker bar around and good tug on the thing confirmed that indeed, I had achieved victory.

The whole ordeal was actually kinda easy once I had the proper tools in place. The moral of this story? If there is a special tool required, just go out and acquire the tool. Of course, now that I've installed the aftermarket pulley, I will have no use for that special tool. So if anybody else is doing the same project, just let me know and I will be happy to send the tool to you.

Epilogue: I managed to complete the timing belt change. I put the underdrive pulley on and with a combination of a rubber strap wrench, fifth gear, a parking brake and all wheels on the ground, I managed to torque that bolt in at about 110ft-lbs of torque. It should be easier to get off next time. It took me forever and a lot of trips to the parts store to figure out the right belt to use with the new pulley. With everything together and some fresh antifreeze, I managed to get the car started and the thing actually ran. Not only that, but it ran well. I took it for a zip through the neighborhood and it seems to have a bit more low end grunt than it used to. I'm going to have to take some fuel economy readings to see if the pulley will save me any gas.

[Frank Lee]

What an ordeal. I usually think of dealerships as "stealerships", but I've gone down there and had them buzz off stubborn fasteners with their nice high-powered air tools... for FREE! Fast, easy, free... what more could you want?

[Twerp]

I considered that. If I had known how much of a pain that bolt would be, I would have had them loosen it for me. By the time I realized how bad it was though, I was already ass deep in disaster. I didn't want to try running the engine with a damaged crank pulley. Even with the extra money spent on the replacement pulley and special tools and, well, I went ahead and found a nice IR impact on ebay for the next time I do something like this... I'm still ahead of the game by a good $100 to $200.

[some_other_dave]

Where'd you get a D-series crank pulley holder for $10? I'd love to get ahold of one, then maybe I wouldn't have to have my mechanic do the timing belts!!

-soD

[Twerp]

Actually, I was mistaken... I got it for $20 on ebay. If you have a 1991 or prior Civic, check out Ebay item #110307523434. Newer Hondas require a different tool, but I've seen those for less than $30. Currently, I'm considering picking up a universal holder because my Tundra is next in line for a timing belt, and if I get too much practice at this timing belt thing, I might end up having to change them for friends and family... I've found one of the universal ones here for cheap.