Topic: This tool is called impact driver....

[Raul CB750K1]

... and I have two of them. I must be some kind of idiot because I've never been able to loosen any screw with them. Actually, once I pinched the palm of the hand with it so bad that I had the blood mark for at least two months, and it hurted like hell!!!


Mine, instead of a ring, have some kind of "twist" action. You push the bit inwards and when it reaches the top you move it right or left depending wether you want to loosen or tighten the bolt or screw.

OK, so I put mine, put the bit against a block wood and slowly push the driver to see in which direction will it twist when whacked. Counterclockwise, we are in the good track.


Then, I choose the best fitting bit, put in in the screw, whack the driver and nothing happens. Should I have to slightly turn the impact driver before the whack? I mean, if the impact driver only turns a few degrees, they could be used before the actual torque is applied, so it would be useless. I've tried anything and never worked, to the point that today I borrowed a set of easy-outs the last two screws of my CB350 resto.


Wo how the hell is used the impact driver??



Raul

[SteveD CB500F]

I think I understand what you're getting at...

I've used mine for 30 years and it's the best tool in my kit!

When loosening, gently turn the driver counterclockwise to take up the slack in the mechanism. Then hit it!

[2000daytona]

For what its worth....I use a heavy hammer (say 3lb) rather than a regular hammer. The extra weight really drives some energy into the stubborn phillips head screw. Some of those screws are really, really frozen after all those years and have to drill them out sometimes. It is all fun wrenching on my 750 K2 and K5. I am obsessed with these bikes!! Happy Thanksgiving to all!!! I will be riding today in Miami although it is freezing (58 degrees) this morning. 

[SteveD CB500F]

I agree.

2 or 3 pound lump hammer is the best.

[Raul CB750K1]

But, do you have to grip the driver firmly? Another thing I've thought is that, in case the bolt is really tight, the torque will be applied as in a counter-reaction, making the driver twist in the opposite direction, isn't it? That is, you can't simply grab the driver with two fingers....


Raul

P.S. I use a heavy mallet with it...

[SteveD CB500F]

Yes Raul, you have to hold it reasonably tight.

The tool is designed to transmit the force through to the screw and doesn't need a "vice-like" grip.

[Jonesy]

I bought mine from Sears and the part you hang onto is knurled all the way around, making it easy to grab. I hold on with my entire hand, and when the bit is seated in the head of the fastener, you twist it in the direction you want to turn the screw when you hit it. If you could take one apart, there is a set of "ramps" that the upper portion rides up on when you twist it. Then, when the hammer hits the top of it, it get pushed down the ramp, imparting a twisting motion to the end with the driver bit. (I hope I explained it somewhat clearly!) The sudden spike in torque, along with the shock imparted to the fastener and the impact force keeping the bit on the fastener is what makes it so effective.

Another thing you can do is use a dead-blow hammer. It's a ball pein hammer with the head filled with lead shot. It doesn't bounce and makes for a heftier impact.

[CharlieVT]

Yeah, I had a manual impact driver for a long time before I figured out how to use it.
Engage the fasterner with the driver tip. Make sure the driver rotated in the direction you want the fastener to go so that is set for loosen when you mean to loosen. On my driver it takes some force to switch from tighen to loosen.  Keep pressure on the driver in the direction you want to turn the fastener while you strike the blow.

If you have a fastener that is all chewed up, put a dab of valve grinding compound the the head of the fasterner before putting the bit of the impact driver into the fastener. The grit of the valve lapping compound will many times give the drive the "bite" it needs to turn the fastener.

Lefty loosey,
Righty tighty   

[Dennis]

I always use a rubber or plastic covered dead blow hammer with mine. Hammer doesn't bounce, much nicer to work with.
And yes Raul, you must twist it to remove the slack from the mechanism before hammering, as the others mentioned.
Good tip on the valve grinding compound, BTW. Works well.

[Bob Wessner]

If you have a fastener that is all chewed up, put a dab of valve grinding compound the the head of the fasterner before putting the bit of the impact driver into the fastener. The grit of the valve lapping compound will many times give the drive the "bite" it needs to turn the fastener.

I have an oil leak behind a cover with a fastener that qualifies for giving this a try. Thanks for the tip. 

[Raul CB750K1]

If you have a fastener that is all chewed up, put a dab of valve grinding compound the the head of the fasterner before putting the bit of the impact driver into the fastener. The grit of the valve lapping compound will many times give the drive the "bite" it needs to turn the fastener.
 

If it doesn't work, can I try with Vegemite?   


I have borrowed a set of extractors that I must return tomorrow. So I will try tonight first the impact driver. If it doesn't work, then I guess it's time for the drill and the extractors.

Raul

[bryanj]

Raul, A good idea is to "tap" (with the hammer) The bit on its own into the screw and then fit the impact driver to the bit and whilst gripping relatively firmly turn the whole assembly in the direction you want to go (usually counterclockwise) then HIT the end with the hammer.

[Jonesy]

If all else fails you can carefully drill the heads off the screws, remove the engine cover in question and then remove the threaded remains (usually easier since you have something to grab, but save this for a last resort). I had to do this on my 750 after the PO was nice enough to grind out any traces of the screw heads- they looked like someone hit them with a counterbore bit in a drill! I drilled the heads off, removed the remains with my fingers, chased out the holes with a tap and replaced them with stainless steel allen capscrews. I could have replaced them with phillips-headed SS screws, but I'm not picky...

[Bob Wessner]

I had to do this on my 750 after the PO was nice enough to grind out any traces of the screw heads- they looked like someone hit them with a counterbore bit in a drill!

Umm, I did this on the retaining screw for my speedometer cable down at the hub  , thank God for extractors. 

[clarkjh]

I did that on mine as well except I drilled a 1/4inch hole about 1/8inch in then drove a Red robertson into the hole, worked like a charm.  The only problem was I broke the damn cable before I drill instead of drill then get the cable out.   Gona cheap out and try JB weld.

James

[paulages]

impact driver=the best tool you can own for working on old bikes.

make sure you have a decent one---it nakes all the difference. i have two: the $4 one from harbor freight is a piece of #$%* and doesn't work very well.

[Raul CB750K1]

KUDOS!!!!!! I was able to remove the last three stubborn screws with the impact driver!!!!

I followed all the advice from you PLUS another thing I haven't done before: I put the crankcases directly in the floor, instead than in the bench. I guess it's important that all the force goes to the screw. I also put the lapping compound, though it was very thin so I guess that it was the right way of hitting and placing the piece what made the real difference.

Now comes another problem with the crankcase... but I'll open a new post for it. Thanks again mates!!!!

Raul

[Rosinante]

I hope I don't piss anybody off by resurrecting this old thread, but I want to point out the importance of having (and knowing how to use) an "impact driver."  I have seen few, if any, fasteners beat this tool.  The cross-head screws so prevalent on these motorcycles can be VERY difficult to remove, and drilling fasteners out because the head is stripped is a HUGE pita.  Bear in mind these are steel fasteners screwed into aluminum case material.  The combination of different metals (causing the contact surfaces to oxidize) plus the vibration of the machine make them very troublesome.

I've got a good one (Sears Craftsman) that I have had for decades.  I choose the proper bit (very important), mount it into the impact driver, and place the bit into the screw head.  I push down on the spring-loaded driver and turn it so it is perfectly in between 'tighten' and loosen.'  I then hit the driver with a hammer a couple of times to drive the bit as deep into the screw head as possible.  It also helps to crack loose some of the oxydization on the threads.  At this point, the driver is not turning during hammer-impact.  Then, when I am satisfied the bit is fitting properly and is seated deeply into the screw head, I turn the handle of the driver counterclockwise, hold it firmly, and whack it with the hammer.  The screw always turns.  I don't use a ridiculous amount of hammer force, but I hit it VERY FIRMLY.  I use a steel hammer.  Dead blow hammers are for blunt force.  Here, you need a SHARP force.  In my humble opinion.