Hello. I just purchased a 1991 Montero LS V6 3.0L 6G72 SOHC with the crankshaft pulley bolt broken off inside the crank. The PO had already started drilling out the bolt. My remedy was the same: to drill it out, run a tap through it to clean out the threads, replace the sheared key and reassemble with a new bolt. If worst came to worst, the last resort is to weld the pulley onto the crank. While removing the sheared portion of the key from the pulley, the key pretty much fell apart. It was corroded very much like electrical corrosion would be. It appeared to be very soft material. Or, maybe it was some type of alloy and the differences in metal contacting each other corroded it. I had the thought that if it was something other than steel or cast, that maybe the crank itself is too. Does anyone know just what the crank is made of? Is it steel? Is it cast? I see that they can be remnufactured so I'm thinking (hoping) that it's not any kind of alloy, which would instill more confidence in re-tapping it as well. TIA for any info or any light shed on this.

Mike

Forged Steel

Thanks for your reply. That helps. I called the local Mitsu dealer too and talked to the parts guy. All he could tell me was he was "pretty sure" it was steel. So I contacted the owner of a race machine shop that remans the cranks and asked the same Q I did here. He told me too that it was either steel or forged. Thanks again!

Mike

Its no problem. Glad yu got the answer needed. They are Forged Steel tho. very durable