Step 1: Measure the part and find out if it can be modified to fit. If the answer is no you can stop.

If yes (and I can help with that part) you may need to do some investigation.

First thing would be to try and find out what it is made of. See if you can find any casting marks. That would be a good indicator that its cast iron (or cast steel).

The black finish is probably Parkerizing (or an equivalent). This has some anti wear properties but is also used for appearance and corrosion resistance. A quick hardness test is to run a file across a surface that is not important. If you can file it you can easily machine it.

It is also easily repaired. Most cam grinders big and small have this process. A call around to various shops may find on that is helpful. You can probably leave it off and not have a problem.

Some hardened surfaces can be machined with a carbide cutter and plenty of coolant I have done this a number of times. You can cut very hard surfaces if you use liquid nitrogen for a coolant directly on the cutting insert. That is probably out of reach of most of usà

Options for dealing with a hardened surface are put the parts in an oven and anneal them, make the changes you need and send them out for nitriding.

You can call the manufacture and ask to speak to a design engineer. Tell them you need to modify certain dimension for a special project and can they tell you the material used and the surface treatment used on the part.

If they have an open mind and donÆt think you are a competitor they may help you out. If they are worried about information disclosure, offer to sign a NDA. Stating you wont tell anyone what they tell you.

As Bob mentioned get a Rockwell hardness test. Look to see if various areas are selectively hardened. This is common with flame hardening and induction hardening. The clutch dogs and wear surfaces may be harder than the rest of the part.

Most times you want the surface ahrd for wear resistance and the under metal soft for toughness. This is how gear teeth are done.

There is so much surface area on those teeth they may not be critical. I would try the file test on them easy cut = soft. Bounces off and leaves a mark on the file = hard.

Good luck,

Kevin