Farmall C123 crankshaft/belt pulley thread

[TommyJD790]

Getting ready to install the front belt pulley on the crankshaft.

I'm pretty sure that I read somewhere that the thread in the crankshaft is 1/2-13.
Bought a long bolt yesterday and tried to thread it in there, but it didn't go.
Looks like the threads a bit buggered up, so I'll have to chase them with a tap.
Just want to make sure I'm using the right one.

Can anyone confirm that the thread in the C123 crankshaft is 1/2-13 ?

Thanks,
Tommy-

[art]

Take a good hard look at your hub! There is a 3/8 x 7/8 long set screw with a jam nut that tighten into the key to hold the assembly on. There is no bolt going in the end of the hub.

[Soundguy]

he's talking about a TAKE DOWN bolt I believe.

IE.. a bolt and a washer stack to seat that interference fit pulley onto the crankshaft snout.

I just did one on my C a while back... can't remember if it was 5/8-11 or 1/2" but DO use a minimum of a g8 bolt

I heated my hub to about 400' int he oven. no hotter or you will ruin the seal. put some grease ont he outside where it piolets the seal.. and put a lil light oil ont he crank snout. hit the snout with some 800 paper to remove any surface rust..e tc..

I used a 3/4" air gun to take mine down

http://www.tractorshed.com/gallery/uptest/a52867.jpg

http://www.tractorshed.com/gallery/uptest/a52868.jpg


http://www.tractorshed.com/gallery/uptest/a52871.jpg

do yourself a favor and loosen the timing cover as you put the pulley on.. let it loosely pilot on the hub to protect the seal.. once on and seal engages hub take down the timing cover.

also.. if area seal rides is damaged.. sleeve it.

use NO loctite or retainers on t he snout.

[scott_vt]

Good Evenin Tommy,
Im just like Chris, I cant remember if its 1/2"-13 or 5/8" -11, although it shouldnt be too difficult to figure out.

When I still had my machining capabilities, I put that pulley in the lathe and counter bored the side that goes on the crank about a 1/4" in, so that it would go on the crank square. I also buffed the bore to cut down on the interference fit. In my opinion it was excessive, and made pulley removal a real pain ! I now have about a .001 interference fit, and as a added safe guard I drilled and tapped two holes for set screws that are tightened down on the woodruff key.

This fix has been in servce fo the last few years with no problems.

You should be able to determine what bolt is in the crank, by inserting various twist drills into that hole, and of course if you have it all apart, there ar allways thread gages...

Good Luck !

[Soundguy]

. I also buffed the bore to cut down on the interference fit. In my opinion it was excessive, and made pulley removal a real pain !

you can sure say that again.. I busted a pulley removing it to change out a crank shaft seal.. and hte new one took my 3/4 gun after lightly polishing the mating pieces and lubing them and heating hte hub.

interference fit is the understatement of the year..

heck.. it's don;t need a set or woodruff key.. you have to break the hub to get it off..

[TommyJD790]

Got the pulley back on, and the engine is back in (on) the tractor.

Just finished doing the ignition last night, and now i'm waiting for a new starter to be delivered.

With some luck (which I have none of), it'll be running by the weekend.

Tommy-

[Soundguy]

hand crank her..

[TommyJD790]

That's what my 8 year old son says. He's anxious to see it run.

Tommy-

[Soundguy]

thought not often, i do hand crank my C.. helps if they are in good tune an all.. and gotta be carefull too.

[DJ54]

Just don't wrap your thumb around the crank, and I prefer to pull up on the crank. Just personal preference on the latter.