104 Update - A spot of trouble

Conig · #1 08-30-2012, 08:54 PM

Follow-up on the front pulley issue. Found lots of helpful threads on the pulling of PTOs and front pulleys including a link to a video that shows how to "influence" the pto off the shaft with a hammer and a piece of wood, and some patience.

My problem? The pto hex head screws. I pulled 4 without issue- note the varying sizes and the fact there were only 5 instead of six). Number 5 came "almost out" before sticking and cracking. I've tried a flat screwdriver, torx head screw driver, and oversized allen wrench (after 3 days of PB). Pics attached, of what came out, and the stuck one.

Any suggestions on how to get that last one out? I'm fresh out of dynamite.

Thanks.
Conig

jkier · #2 08-31-2012, 07:41 AM

Time to break out the drill.

Start with a small dia bit and pilot the center of the set screw, then work your way up to just under the screw dia.
I prefer to use left handed bits for this as they sometimes influence the screw out.

You'll need to case the threads with a tap before you try putting new screws in

PaulS · #3 08-31-2012, 07:50 AM

If that were mine it would depend if this was the top one or the one that actually holds the pto on. If it is the top one, the locker, you absolutely have to get that one out to get to the one underneath. If it is the under one it looks like it is backed off the shaft to enable you to remove the pto with it stuck in there. If it is still touching the shaft then removal of the allen screw is necessary before trying to remove the pto. The job of screw removal should be easier with the pto off

Conig · #4 08-31-2012, 09:01 PM

PaulS - Yes! it was a bottom set screw and it was out far enough that another night of PB Blaster followed by a wedge of wood and the rubber mallet and the PTO came off the shaft easily. Thanks for the suggestion that it might be clear enough to come off.

jkier - I'm sorry I don't speak fluent "mechanic". What does it mean to 'case' the threads with a tap? And once I drill a hole in the stuck screw, how do I get it out? Thanks for the help.

And then the next step is some sort of a device that pulls the bearing (?) off the shaft.

Repairing a Cub, one set screw at a time...

PaulS · #5 08-31-2012, 09:19 PM

I think what he meant was chase the threads with a tap meaning run a tap through the hole when you get the screw out to straighten any boogered threads. If it were me I would soak it some more with penetrating oil from both sides and see if it will turn in and possibly take it out that way. If not try a tap once you get it all the way in and dress the threads up where it got stuck.

Conig · #6 09-01-2012, 08:27 PM

PaulS - Thanks for clarifying. So I got the PTO off and have it in my bench vise (padded for protection). I've tried drilling out the screw with a bit that is just marginally smaller than the screw itself (the smallest 'easy out' I have may still be too big). The drilling is slow going. I'll post an update when I'm done.
Conig

Conig · #7 09-04-2012, 06:06 AM

An update- the set screw came out, split in several pieces, under the influence of the 3rd drill bit. Can't say I did the threads in that particular hole any favors, although I did pass one of the set screws back down carefully and it seemed to seat, and hold, at the very bottom of the hole. Further up, where the locking set screw goes, not so much. Will work on re-threading that hole. Now onto the front pulley.
Conig