The Stovebolt Site Forums The Shop Area General Truck Talk open driveline conversion snag on my 1941

I'm in the process of changing out the closed driveline pumpkin to an open driveline pumpkin. In order to pull the axles I need to take out that little lock screw that holds the pinion shaft inside the differential. My problem is that the pin at the end of the lock screw must be broke off 'cause all I got out is the screw portion. Don't know what to do.

John:

I know my ’41 ¾ ton is a bit different but pulling the axle shafts did not involve the pinion. It was a matter of pulling the back cover off slipping the pin out of the spacer between the spider gears , pushing the axle shafts in slightly and slipping the horseshoe keepers off of the shafts. They came right out

Maybe I wasn't clear enough. This pic belongs to another stovebolter "Cavebull". But this is the screw that's giving me problems. The pin at the end must be broke off and is still in the hole. Look here.I need to pull the whole lock pin so the shaft can slide down so I can push the axles in to get the C clips out.

You might be able to get the rest of the pin out with a strong magnet and a steel pick. You'll need to get the pick in contact with the remainder of the pin, and magnetize it. I won't quarantee the pin will come out, but I have done that trick in the past. I have also heard of guys using a coat hanger and a stick welder to get the pin out. The hanger is bent to access the end of the pin, then is clamped in the + cable from the welder. Hit the power to tack the hanger to the pin and pull it out.
This is actually a pretty common problem, it usually happens when the diff is assembled at the factory.

I've drilled a 3/16" hole on the opposite side of the spider gear cross pin down to the level of the broken-off pin, and used the point of an awl to work the pin out of the hole. Once the end of the pin is exposed, a piece of stiff wire like a clothes hanger can be bent and forced into the hole to keep the pin moving. The hole doesn't weaken the carrier in any way.
Jerry

That's a pretty neat trick, Jerry. Going to have to remember that one next time I run into that problem.

This works most of the time. Drill two holes in a piece of 3x3x1/8 angle so it will bolt to the two holes at the top of the housing. Make a slot for a flat bar to fit into about halfway between the two bolts and in line with the end of the pin. Have a helper place the bar in the slot and swing it down to a spacer on the end of the pin. I have a clevis on the flat bar so it's easier to hold in position. The helper can apply enough pressure on the end of the pin to keep the stub of the lock pin from spinning. There isn't room for a drill motor so get a 10 or 12 inch long 3/16 drill and a short piece of 1/4" tubing that's long enough to fit against the broken off lock pin and sticks out just enough to grab hold of; this will keep the drill centered on the pin even if broken at an angle. These pins are VERY soft so usually the long drill will hang part way through and pull the pin with it when you withdraw it. If not GENTLY tap an easy out into it and remove. It is soft and thin walled after drilling so bashing a remover in hard will swell it and really lock it in. If you do the arcing a stiff wire against the stub use a piece of shrink tubing that is even with the end of the wire to prevent accidental arcing to the sides of the bore as this will make it hang up for sure. As suggested, get the wire in position first and then bump the outer end with the stinger.

Thanks for all the suggestions. I did what Hotrod Lincoln mentioned. Except I misunderstood. I didn't realize that the lock pin actually protruded about 1/16" beyond the spider gear shaft. I drilled the hole on the bolt head side of the shaft to sever the lock pin. It took a little pounding on the shaft to get the remainder of the lock pin to bust through the casting but I got that sucker out. It's was a little brutal but I don't plan on using this differential anyways 'cause I'm converting to an open driveline. I shoulda drilled the hole on the other side of the shaft like Hotrod Lincoln said and it would've worked like a charm, but it's all good now that it's out.