can't undo flush screws behind clutch

[79-GS550-L]

Hi everyone,

I'm trying to split the crankcase, following instructions in the haynes manual. I've got the kickstart spring, clutch, and oil pump out, and now there's a plate behind the clutch holding in the large bearings around the tranny input. It has 3 countersunk phillips screws holding it in (also there's a plate behind the kickstart shaft with 3 of the same screws). I can't get these screws out at all! I bought an impact screwdriver like the book says to use, but even that is just stripping away the heads. Maybe I'm not using the tool properly... I tried just holding it firmly and hitting it, but I can't keep the handle from rotating, so I tried holding the handle with some channel locks and banging on it, but still no luck. I'd really hate to have to drill these out!

Any suggestions?

[TheCafeKid]

You want the handle to rotate...but in the right direction. its what breaks the screws loose. once you get them to break, i would suggest a reg screwdriver however, as some of those impact drivers can be a bit unwieldy. YOu may need to smack it pretty damn hard, and if you start to mung the heads out...try using the #3 bit instead of the two...

[tkent02]

Impact 101...

You need to push the handle down, and turn it in the intended direction untill the spring is compressed, and you can feel the "ramp" which causes twist when you hit it. Cheapo impacts have springs which are too strong, especially if the threads are chewed up already, without a little bit of grip between the tip and the screw you can't feel the ramp correctly. Sometimes you can take the tip out and lightly tap the tip into the screw to make the fit better, get a little purchase there.
I would suggest practicing on something a little less difficult to repair, get the hang of it.
They work really well with the right technique, you may need a better fitting tip or maybe need to cut a slot in the screwhead, hard to do with flush screws.
You could also try a sharp center punch, use it at an angle on one side of the screwhead to induce turning, not likely to work very well either.

[rapidray]

First of all, those screws TAKE a #3 tip NOT a #2. If you use a #2 you will screw up the screw heads in the first place. Second, now that they are already messed up just put some grease on a 3/8 drill bit & drill the heads off. The grease helps catch the metal being removed. Then the screws will back right out. Get new screws & use the Suzuki thread lock to reinstall. Good luck, you can do it! Ray.

[BlackStar]

I just went through this myself. Use the correct bit as explained above. Pre-load the impact driver as explained above. See if the bit holder will pop off of your impact. Mine does and there is a 3/8 square drive nose. Use a 3/8 extension so that the impact is up out of the crankcase, makes it a lot easier.

[79-GS550-L]

well, I've managed to break the impact driver! ...but the screws are not budging. The slots are starting to get a bit chewed but there is still enough metal for the bit to grab.

I'm using a #3 bit (with a short extension), and preloading the handle until it hits the ramp. Now, I'm pretty sure I've got the direction right... when I push in on the handle, the handle rotates clockwise, which means if I hold the handle firmly the bit rotates counter-clockwise. Right? I used it on a different screw and the screw turned the proper way, but that screw wasn't tight.

Anyways, after banging away on the driver for a while, I could feel the ramp starting to get notches in it. Now the bit won't move at all, it's stuck in there, and I can't even get it to move with pliers. Maybe it was a bad idea to clamp down on the handle with channel locks, but it was really hurting my hand! The handle is chrome with a serrated grippy texture stamped in it, and when I would hold it and smash it with the hammer it would twist. Felt like grabbing an electric sander!

Drilling them out is still an option but I'd like to leave that as a last resort... but if I do drill them out, how on earth am I going to be able to grab the shafts to remove them?

[bwringer]

Sounds like you have two problems: a crappy impact driver and the wrong technique. Those screws aren't that long, although they are held in with Loktite and need a good pop to come loose.

1) Head to Sears and get a decent quality impact driver. Cheaper ones lead only to heartbreak. The ones at Harbor Freight and most auto parts stores are the same crappy quality, although a "real" pro auto parts store like Napa or Carquest will have good ones.

2) Use the CORRECT bit - in this case, a #3.

3) insert the bit into the tool and seat the bit into the screw.

4) Twist COUNTER-CLOCKWISE while pressing lightly against the spring. You should feel the tool extend to its full length and stop rotating. Keep inward and counter-clockwise pressure on the tool.

5) Give it a smack with the hammer. You should feel the tool compress, and the ramp inside will rotate the bit counter-clockwise a 16th of a turn or so.

6) Once it's broken loose, you should be able to unscrew the fastener by hand.

[chef1366]

Ditto. I have a Crapsman and it has never let me down.:-D

[psyguy]

i don't think any thread locking compound would witstand the use of an impact driver so i'd suggest you practice your technique
when you hit the impact driver with the hammer the driver handle should NOT rotate in your hand - make sure you PUSH the handle INWARD (and counter-clockwise)

[79-GS550-L]

yes I was using the harbor freight $6 special. I'll try a craftsman next time...

I'm confused about the direction of rotation though. You guys say to twist the handle counter-clockwise until the tool expands to it's full length. My impact driver starts out at full length, when you twist the handle it compresses and becomes shorter. The bit turns opposite the handle, so wouldn't I want the handle to be able to turn clockwise?

Then when I pop it with the hammer I imagine I need to hold the handle firmly to prevent it from rotating, otherwise it just compresses and rotates the handle and the bit stays fixed. So that's why it was tearing my hand apart - either the handle rotates or the bit does. The bit is held REALLY tight, so my hand is the first thing to give. That's why I tried the channel locks.

Am I wrong about the rotation direction? I sure hope I haven't been tightening those screws in even more, but the wear on the screw heads looks like the bit has been twisting CCW as it should.

[BlackStar]

I got my impact at Autozone. I think it is a Great Neck. I used it on the exact same fasteners you are working on. So far it has not let me down. I'm finding that there appears to be different grades of chinese tools! Actually now that I think about it, it's made in taiwan, which I hold a little higher than mainland chinese stuff.

[spchips]

I like to thinK I'm pretty good with an impact driver. However, these are probably the worst ones on the whole bike. I don't know if it's a softer metal or because they are flush type, but they just suck. I wouldn't feel bad if one or two have to be destroyed to get them out.

[psyguy]

my impression that you're using the tool the wrong way is getting stronger... :shock:
mr bwringer explained it nicely step by step, so just follow his directions
and again - you need to compress and twist your tool counter-clockwise
when you hit it with the hammer the driver bit only rotates - there's no further major compression of the tool handle

good luck and do let us know how you go

[79-GS550-L]

hmm. So to be sure I've got it, you compress the tool completely? I just don't understand how hitting the fully compressed tool would make anything rotate at all Also, how would the tool know which direction to turn? The ramp is kind of a parabola... you can twist the handle CW until it fully compresses and then decompress it CW, so that now it compresses CCW. At full compression there's kind of a flat spot, it could turn either way. Maybe I should post a pic of the tool, this kind of thing is hard to explain in words :shock:

[psyguy]

this is turning into a comprehensive tutorial

you compress and twist the tool handle by your hand as much as you can (against the spring in the tool that is "stronger" than your hand)
when you smack it with the hammer then the force of that smack is much greater than what you can apply by your hand only and the forward direction is translated into a rotating action of the end bit
you "tell" the tool which way to turn by initally twisting it that direction by hand
hope this clarifies enough [-o<