Wondered if anyone else had seen this and had a solution?

I'm helping some friends replace a Skytech lightweight starter in a Mooney 201, and when the old starter came out, the aft alignment pin stayed in the case pad, didn't come out with the starter.

We've tried vise grips, heat, mouse milk, light taps with a hammer, so far no luck. It's like the darn thing was pressed in with a 4 ton press. Any ideas? It's this pin:

Those pins are hard!...tool steel, i think. It's stuck in the mounting pad on the engine case? You might try to grind two flats into the pin. Then you could get a wrench on it to apply some torque. Of course the pin would be unserviceable afterwards.

Carbide drills or some good quality TiN coated drills will drill tool steel. Very Carefully mind you.

I have had some success using super glue and tight fitting hex nut. Use the hex nut to apply some rotation force or if you have room you can use it to pry the pin. Make sure you do not allow the superglue to run down into the pin bore. Since you have had vice grips on it you may have already chowdered the pin diameter and that may or may not help.

If you need to remove the nut you can use mild heat and some acetone or iso propyl alcohol to remove the super glue.

If those don't work I get out the slide hammer with a collet on it and see if a good thumping will pull it out. This is location dependent.

Past that it usually involves a welder to attach something to it so i can pull it.

It's most likely galled or corroded into the aluminum.

Might dry some dry ice, see if you can shrink it.

This is how good mechanics earn their money.

be careful using a stud extractor etc. You can take a chunk out of the case if it's really corroded in there. The mention of dry ice is good. I would alternate dry ice and heat (from a heat gun, not a torch). You need to exercise the corroded joint with some thermal expansion/contraction to develop some cracks through the corroded interface to allow some penetrating oil to wick through.

patience is key. Don't turn a small problem into a big one. It might take a week to get that thing out, working on it every evening - compared to breaking the case that week would be just the blink of an eye

good luck

I've had good luck with this when dry ice is not convenient.

Many complicated ways to skin this cat.

The dry ice/heat cycling is best for breaking loose corrosion and popping that guy out. I'd start there.

Alternatively any machinist with a hobby lathe could turn a little drill jig so you don't damage the case or slip off the stud. You drill and tap a center hole in that stud without screwing it up, then you use a puller or a bolt through a large socket to pull the stud out.

Or you could weld a nut on the stud with a bit of a gap between the nut and the case and use a prybar... but this could also end up damaging the case.

Del, the Aussie's and Brit's I've worked with have access to this -50°C spray in lieu of dry ice. Your's looks colder.

EDIT: I did some math. -50°C is basically -60°F for marketing sake... gotta be the same chemicals. Your's is available in the USA though.

hey Del,

Agree that stuff is awesome
The dermatologist used that same stuff to freeze a thing off the top of my head. I had never seen one before. I immediately thought about the farmall cylinder head in my garage and the valve seats i was struggling to get out. I asked him where i could buy a can and he tossed it to me, said I had already bought that one as soon as he used it. Apparently for medicine it's one can per customer - pretty wasteful.

Thank you all for the replies, will let you know how this turns out.

I would consider leaving the pin alone and simply remove the one from the new starter and install. All that pin does is hold the starter in alignment, doesn’t matter if it stays with the case or the starter, at least from an operational standpoint.

My concern would be damaging the case or enlarging the hole, then you would have a problem. Much safer to limit the extraction efforts to the starter rather than the engine.

Just use a dowel pin puller. It's nothing more than a collet that grips the pin and uses the threaded shaft to pull the pin out. I have several different types including one that works like a slide hammer.

https://www.amazon.com/Cal-Van-Tools-95 ... g=btalk-20

Dave

Well, heat, freeze, pliers, vicegrips, die grinder, and 4 different kinds of rust penetrants didn't do it, so the new starter went on minus it's aft pin.

Ops Check good.

Thanks for all the suggestions though, we gave most of them a try and we may use some of those tricks in the future. That pin just wanted to stay there.

At one time I hung out with a dune buggy crowd. They tried to get every extra cubic inch out of their VW engines. Some had stroker cranks built up. this entailed welding up the up of the rod journals and then regrinding the crank pins and re heat treating the entire crank shaft such that the stroke was increased.

The flywheel was held to the crank by four or on extreme cases eight dowel pins and a single large bolt through the center. Pop the clutch hard enough with a strong enough clutch would shear off the dowel pins flush with the crank. With many hundred dollars invested in the crankshaft there was a market for salvaging the crank by removing the dowel pins. Those shops that did this were very secretive of the method employed. I caught one of the experts who told me that this crank was the last one that he would ever do as he was giving up his shop that day. He agreed to divulge the secret of the process.

His method was to grind the exposed end of the dowel pin so that there was a flat spot so that a drill would not wander. Then he carefully with a tungsten carbide drill bit and copious lubrication would drill through the dowel pin. Then fill the cavity with thick grease such as wheel bearing grease. He then used a drift punch that was the same diameter as the hole in the dowel and with one sharp hit, the hydraulic pressure would pop the pin out. One of the tricks was to use the smallest diameter of drill/drift punch to develop the greatest pressure and have the maximum surface area on the dowel pin to work on.

I like the idea of leaving the pin and pulling the one in the starter.

Out of the box thinking at its best!

Or the Lucy problem solution: No problem too complex to run away from!!

BH