Removing Broken Set Screw And Dust Screen Screws
 

Well now that I no longer have a motor for my 122 its time to turn my attention back to the 147.

One of the set screws in the front pulley broke. How exactly should I go about getting it out? Would a normal screw extractor work? The PTO part of the pulley is in the way, I'm not exactly sure how to get around that.

Also, the four screws holding the dust screen are frozen in there. I tried a good soak with PB Blaster and still no luck. Would heating them with a torch be a bad idea?

Can you get to the set screw with a left hand drill bit? Also, I don't think heat would hurt.

Try a 50/50 mix of actetone and ATF (not synthetic!) Soak it with that and maybe a little heat. Make darn sure you let the actetone evaporate off before using heat.. This works better than PB blaster or anything else for frozen screws..

If it is the front pto we are talking about on a NF, then I would remove the hood, disconnect the + batterycable, remove the VR [ just the 2 mount bolts and rest on motor] and the wire harness hold. Take off the front cast iron front grill and get in there and work. :RTFM:

I'm not sure if I would be able to find that small of a bit long enough to reach that far as the PTO shroud or what ever you want to call it is in the way.

Maybe I'll try that mixture.

And the motor is out of the tractor lol.

You might also want to use a .30 caliber bore brush in a drill and clean out the threads before trying to back the set screw all the way out.

The head of the set screw is sticking about 1/4 out of the hole already, so that wont work.

Jmroy, do you have a picture of this set screw?

I'll take one later.

Push the center button on the PTO and it should turn so the notches in the basket will line up with the set screw holes.

Heating the bolts will only make them twist off easier. Normally, once steel bolts are frozen in aluminum, that's where they stay.

Finally got around to take that picture now that the snow is all gone and I could get to my 147. Here's a picture of the set screw I was talking about. Like I said, the PTO basket is in the way of getting a drill in there.

http://www.jr.bz/setscrew.jpg

Great pic! Thats Crystal Clear!!
I can't remember how long the screws are- are they backed off the shaft? If they are, then get the pulley off the crankshaft. You may have better luck driving them through to the bore. The broken one could have a slot ground into it with a dremel tool then use a flat screwdriver.

I had to change that pulley on my tractor, I am sure my set screws when tight against the crank were below the outer part of the pulley, have you tried to get the pulley to move on the crank? Adding heat to the pulley would help loosen it up.

If all else fails, you could cut the pulley off the center hub, they cut the center hub of the pulley with a cut off wheel (a dremel tool might allow better access to it). I would make the a single cut over the keyway (avoiding damaging the crank) that completely severs the hub at that point, then rotate it 180 degrees and cut like 3/4 to 7/8 of the way through to the crank there. Then rotate it back to first cut and use a sharp chisel and drive it towards the key trying to spread the hub and it should come off. You may have to make several relief cuts around the hub to get it to spread with the chisel.

I am sure the last method would work, of course you will totally destroy the S/G pto clutch drive pulley in the process, but it has to come off to rebuild the engine....or take a sawzall and cut the crank off behind the pulley...of course, the pulley would be a lot cheaper to replace.

I think its all the way in, I was able to remove the other set screw and when I put it back in it is roughly the same height as the broken one (a little talker maybe because of the key). Cutting the basket off the pulley is probably a feasible idea. Would a chuck extension work for the drill to use a bolt extractor?

It should, but I don't much faith in the bolt extractors in this situation. They seem to work the best when removing busted off bolts threaded into cast iron, not so great on steel to steel or steel to aluminum. But. if you have access to them, I sure would try them, just a little bit of time, may save buying some parts.

I think I would grind down the head flush as possible, center punch the bolt, drill a small hole down the center of the bolt as best as you can. Then progressively get bigger on the bit size, left hand bits are great....they create a lot of heat and have had fairly good luck with them backing the bolt out.

Me being me, I would be pi**ed off and cut the crap out of the pulley and get it off the crank....LOL.