Clutch Spring Cap Screw Modification

[XSLeo]

Harbor Freight Has upgraded there hand impact wrench since I looked last.
It has a red plastic handle that flares out on the end you hit so your less apt to hit your fingers and comes with 6 bits. The usual four two sizes of Phillips and straight and two longer bits one the # 3 phillips and the 8 mm straight. All in a blowmoulded case.
Very nice looking.
#37530, $7.99 with the 20% off coupon $6.39, Can't hardly beat that.
You find there coupons in many magazines. Often they have them on the web site.

 

[Classic]

Classic, did you try a hand impact wrench to loosen those screws? Drive the bit into the screw then put the hand impact on the bit then push in and turn the impact in the direction you want it to turn then hit with the hammer. They should pop right loose.
If that wont work, a small cold chisel held at the right angle and hit with a hammer can get them loose.
Once they are out modding them for an Allen head bolt is easy.

No, just put 200lbs behind the correct size phillips wrench. 4 came out with ease but those two rounded out immediately.

 

[xjwmx]

#37530, $7.99 with the 20% off coupon $6.39, Can't hardly beat that.

Oh yes you can. It's only $3.99 at the moment. LOL! When I see something like that I feel so grateful that I want to buy a dozen of them as a reward.


But this modification...I was curious how many drill bits do you go through doing this? What's the best bit to use?

 

[Classic]

^I'd also like to know.

And good news. I got a shallow phillips #3 and hammered it in. My clutch is off now.

 

[XSLeo]

One drill bit should do dozens of sets. Use a bit of oil on the drill bit.
I've thought about getting in the insiders club, just haven't yet. I think I'll do that.

 

[gggGary]

What Leo says; lots of oil for cooling, fairly low speed consistent pressure. The goal is a nice coil of steel curling off the drill bit. You won't always get that but you should be seeing chips not metal dust. Bolts are tough not hard and tend to machine well.

 

[oldbiker]

hi guys when i loosened the phillips head screws on the clutch hub i did have the benifit of an air operated ratchet with carbide phillips head bits ..and all except 1 were easy...and i got to use this tool i didn,t know i had... it was a complete rattle gun /air chisel /ratchet with fittings from bunnings.....regards oldbiker

 

[crashcourse]

Machining speeds (in rpm) are pretty standardized. Use a chart like this one to find surface feet per minute (sfpm) for your material, then one like this to find out what speed to set on your machine for how big of bit you're using. Carbide cutters can go 4x faster than HSS (regular steel drills/cutters). Like was said, using the right cutting fluid will greatly improve surface finish and tool life. Also, for more precise holes, invest in a center drill to start your holes. And a small shop grinder with a good sharpening wheel can be really handy when your tools get dull.

 

[rayth]

This is a great and sensible mod- obvious but I never thought of it
I will do this - before she goes on the road - many thanks

 

[JP50515]

Machining speeds (in rpm) are pretty standardized. Use a chart like this one to find surface feet per minute (sfpm) for your material, then one like this to find out what speed to set on your machine for how big of bit you're using. Carbide cutters can go 4x faster than HSS (regular steel drills/cutters). Like was said, using the right cutting fluid will greatly improve surface finish and tool life. Also, for more precise holes, invest in a center drill to start your holes. And a small shop grinder with a good sharpening wheel can be really handy when your tools get dull.

Somebody's been in the machine shop for a while. Ha this ^ is the story of my life right now, going to school for machining.

 

[5twins]

The hardest part of this mod is holding the screws for drilling. I made up a wooden holder but the screws got so hot, it started smokin', lol. Then the screws started spinning in it. My second attempt was better and succeeded, using aluminum .....

A note about what length Allen screws to use. The originals are a rather odd 42 or 43mm long from the top of the head to the bottom of the threaded portion. Commonly available screw lengths are 40 and 45mm. The 45s are a bit long and can stick out of the back of the hub, rubbing on the outer basket. The 40s, on the other hand, barely make it. To overcome this and give those 40s an additional MM or 2 of grip, grind the domed top of the original screws flat after drilling them.

 

[WagXS]

So suggestions are to grind 2mm off top of oringinal screws or to countersink 2mm into original screw?

You can also find either "button" socket head bolts or "low" socket head bolts at Ace Hardware or local Fastenal so you don't have to grind or countersink, any recommendations on these bolts?

 

[5twins]

You're not grinding because of the head style, you're doing it to gain some length on the threaded end so it goes into the hub deeper. Normal Allen heads fit fine so there's no need for the low heads or button heads, but I guess you could use them if you like.

 

[WagXS]

Oh. Got it, thx. So what's the problem with countersinking that another guy had a problem with. Is grinding the better option?

 

[5twins]

He either countersunk them too much or used bolts too long, or both. The bolts stuck out the bottom of the inner hub and rubbed on the outer hub. Just make sure your bolts don't stick out the bottom when installed.

 

[WagXS]

Completely understand stand now. Thanks for spelling it out. I'm performing the mod tomorrow. Wish me luck and thanks for the help.

 

[XSLeo]

Once you get the stock bolts drilled, mount the drilled bolts to the hub with the bolts you plan to use. Now look at the back of the hub. Do the bolts stick out? Do they come out flush or do they not come out to flush?
I would reccomend using bolts that stick out a bit then grinding them back to flush.
This way you know you have the right length bolts.
Leo

 

[YL82]

Since I'm not properly set up with table-top tools to do this mod (and otherwise lack the time needed for fabrication), would I be better off to go with MikesXS Clutch Spring Screw Set (#39-6508) which uses socket head bolts with matching sleeves in lieu of using a new set of OEM Phillips head clutch springs screws that I've already purchased (which I'm sure I can return)?

While going with socket head bolts is a plus vs. trying to torque Phillips head bolts, I have to wonder about the thread length/cap length on this product in light of comments I've just read (about unequal torque on threads). I don't have much confidence in their customer service to provide specs of this nature.

Any happy customers out there who have purchased MikesXS $33 Performance set?

 

[5twins]

Original screws in good condition (Philips slots not buggered up) are not a problem. If you use the hand impact for removal and keep the heads in good shape, they work fine. For install, you can torque them using the #3 bit from your impact fitted into an 8mm or 5/16" socket on your torque wrench.

 

[YL82]

That's great news! Thanks, 5twins.

Yes, I mangled a couple of the screws during removal, so I ordered a new set of OEM's.

I'll just use those and follow your install recommendations.

What is the proper torque?

I really need to pick up a hand impact wrench.