Topic: Impact driver on valve cover screws

[Maurice]

Hello,

search didn't yield much... I need to rebuild the top end, 77 CB550 engine, it's smoking and I can see oil coming out the exhaust valves. I am faced with some valve cover screws, JIS head, which just want to round off. I am using a philips #3 bit, not ideal but oh well.

Now, before they strip completely I'd like to try using a hand impact driver. Given the location of those screws, am I likely to snap off the pieces of head where they screw in? How strong is that part?

Anyone have experience with this or am I just safer drilling them out? Allen button heads are on the way.

Thanks!

[toytuff]

I have had great success using this tool on engine side cases. Lowes carries two sizes so buy the larger. Use the biggest Phillips head bit. A little heat will help. Set the tool in neutral position.

I also rotate the bit in the head of the screw. Try a little force, remove, turn 90 degrees and try again. Seems like they are just about to round out then you here a snap as it breaks free. I have wished several out and it worked! 

I would order new screws afterwards.

tt

http://www.lowes.com/pd_239377-16878-60233_0__?productId=1067895&Ntt=kobalt+multi+drive&pl=1&currentURL=%3FNtt%3Dkobalt%2Bmulti%2Bdrive&facetInfo=

[Maurice]

Ok, so no risk of throwing tools around and cursing in 3 different languages when that ear on the head falls away with the screw firmly seated in it? Hasn't happened (yet), don't want to start either. I imagine that I should start with something like a rubber mallet, in case?

Gosh this is stressful...

Yes screws are on order, stainless steel allen button head.

[Bankerdanny]

There is always a risk, but it's minimal. I have used a hand impact successfully to remove those screws. It ususally only takes a couple of whacks.

[toytuff]

Use both hands on the driver. Also, pick up some anti seize when reinstalling.

tt

(I was going to say "use both hands on the tool" but figured that would get way out of hand)

[Maurice]

Use both hands on the driver. Also, pick up some anti seize when reinstalling.

tt

(I was going to say "use both hands on the tool" but figured that would get way out of hand)

Wait... how do I whack with the hammer? I do not trust a third party wielding that kind of tool around me or my bikes...

Thanks for the suggestions guys

[MCRider]

There is always a risk, but it's minimal. I have used a hand impact successfully to remove those screws. It ususally only takes a couple of whacks.

If it takes more than one hit, your not whacking it hard enough. 

I always wear a thick glove on the holding hand and use a 2.5lb ball peen hammer. Then SMACK it.

[Bankerdanny]

Just make double sure your have it set to loosen and not tighten, otherise a cracked cover is almost guaranteed (ask me how I know)

[Cougars750F0]

Apply PB Blaster first and give it some time to soak in.

[Maurice]

PB Blaster, good idea.

I'll try the drill. When you say "speed" I assume you mean the number on the clicker ring thing that sort of provides some impact simulation? Didn't think of that. Need to charge it and report back.

Hope I don't have to drill any... The oil pump ones I was able to get with a chisel without driving it through either the engine case or pump itself, but it sure was some serious buttcheek-pinching time.

[Bill/BentON Racing]

I took out about a 100 or so last week. Heat, rust penetrant,etc all help. Took all out last week just impact driver,#3 bit,a long one,make sure tools set rt.,take up the slack in the direction you're going,and whack it, I use a 2 lb brass hammer. One to two hits should do 90% of them,good luck, Bill

[Jerry Rxman Griffin aka MuthaF'er]

You are trying to make this difficult. Use the larger bit. Preload the impact driver with your left hand by pushing down and turning counterclockwise and whack the #$%* outta it with a REAL hammer, not a plastic or rubber one and it will turn. It's that simple. PB Blaster and a glove are a good idea.

[Bill/BentON Racing]

+1, it ain't that hard!  Bill

[LesterPiglet]

Don't use anything other than a real hammer on an impact driver, rubber/leather will not work.

[Maurice]

Success! As luck would have it Amazon delivered the hand driver today. 3/8" bits at that, and I didn't break anything.

The tools that saved the day (OTC, ordered on Sat. at about $18, right now out of stock):



One of the screws in question:



You can see how it's starting to strip, but the above tool grabs just fine.

Now I feel like a chump it was so easy. In terms of technique, pre-loading the driver, as Jerry...MuthaF'er said serves two purposes: prevents slop between screw and bit, and also tells you that it's set to go off in the correct direction (if not it turns, at least this driver does).

Thanks all!

[Powderman]

Did I miss something here. Why are you using phillips bits on JIS screws? Why not get the proper tips? Should make getting them out a bunch easier. Phillips is what probably stripped them to begin with. They are a completely different slot design.

[Jerry Rxman Griffin aka MuthaF'er]

Maurice, I like the hammer but WTF is that other thing? Please search for IMPACT driver.

http://www.sears.com/craftsman-impact-driver/p-00947641000P?prdNo=1&blockNo=1&blockType=G1

Glad that thing worked for you. Has anyone else ever seen one of those? Guess I'm just old school 

[Powderman]

Maurice, I like the hammer but WTF is that other thing? Please search for IMPACT driver.

http://www.sears.com/craftsman-impact-driver/p-00947641000P?prdNo=1&blockNo=1&blockType=G1

One is a cheap impact driver and the other is a Harley Davidson Fine Adjustment Tool

[brewsky]

Whatever tip you use, dip it in valve grinding paste first, then lightly pound the driver (or tip) into the screw head till the screw will support the driver by itself.

I usually clamp vice grips to the screwdriver, push in and hold with one hand, and give a sharp, quick twist with the other. That way, you can tell by feel before you strip the head.

Or, take the chuck off the hand impact and put it on your air impact, just be gentle with the trigger.

Or, maybe just get the Ferrari of JIS screwdrivers:
http://www.vesseltools.com/hand-tools/screwdrivers/impact/980-series/flypage.tpl.html?pop=0

[dave500]

when you reinstall it dont winch down those front four little ears,thats when youll snap one off,let the other bolts pull the bulk of the spring tension down and just chase those along as you go,finally nip them down once the cover is squared way.

[Maurice]

It's an OTC impact driver, its list price is actually more than the sears listed. I've had good experiences with OTC tools when working on Jeeps and this one did not disappoint. Just thought I'd share, I had never come across this OTC tool before.

I am aware of the difference between JIS and Phillips, but I want to replace with allen head whenever I meet one. This driver with its bits seems to do a fine job at loosening even with partially worn heads. BTW a trick I learned on another list (hawkgtforum IIRC, to give credit where it's due) is to grind down the tip of Phillips bits just a tad to give them more grab in JIS screws. It's still not ideal but helps some, and in this case I actually didn't have to do it, it worked flawlessly as is.
 
I'll heed the warning about getting them tight, especially in allen head form.

Thanks for all suggestions and advice!

[Bankerdanny]

I have a JIS screwdrive set, it doesn't matter when the screws are corroded in place, the screw heads will still strip. I have never seen JIS impact bits.

[Powderman]

I have a JIS screwdrive set, it doesn't matter when the screws are corroded in place, the screw heads will still strip. I have never seen JIS impact bits.

You haven't looked:
http://www.ebay.com/itm/New-Vessel-JIS-431801-Replacement-Bit-Set-2400-2500-/380748854776?pt=LH_DefaultDomain_0&hash=item58a66675f8

You can get them straight from Vessel ( http://www.vesseltools.com/hand-tools/screwdrivers/impact/431801/flypage.tpl.html) for $10.16, shipping might make it a worse deal than the Ebay listing

[brewsky]

I have a JIS screwdrive set, it doesn't matter when the screws are corroded in place, the screw heads will still strip. I have never seen JIS impact bits.

You haven't looked:
http://www.ebay.com/itm/New-Vessel-JIS-431801-Replacement-Bit-Set-2400-2500-/380748854776?pt=LH_DefaultDomain_0&hash=item58a66675f8

You can get them straight from Vessel ( http://www.vesseltools.com/hand-tools/screwdrivers/impact/431801/flypage.tpl.html) for $10.16, shipping might make it a worse deal than the Ebay listing

Here's a set for regular 1/4" drive:
http://www.vesseltools.com/hand-tools/screwdrivers/impact/431701/flypage.tpl.html

[Maurice]

All this talk of JIS from grown men is... disturbing 

Thought you guys might find this interesting. Unbolting the breather cover and this came out. I was like



This particular bolt was loose.

I think I'll start a separate thread on rebuilding this top end, would like some opinions on what I'm seeing it's the first time I'm doing this.