just want to share a problem i have come across a couple of times, and i know one other has mentioned it on this forum also. Just the other day i discovered that again i have sheared the crank pulley pin do to the strain the charger puts on the crank pulley. All last week i was wondering why my car was dropping boost as i went through the rpm range, i thought my belt was slipping, and i tightened it and tightend. But that was not the problem. The crank pulley was spinning on the crankshaft, luckely i put enough lock-tite on the pulley bolt that the pulley wasn't in a full free spin, which would have left me on the side of the road (and i have had that happen once before).
Solution to the problem... I strongly sugest to and supercharger owners to do this>
instead of using the toyota 9cent pin, i cut the end of a 1/8th inch drill bit (case hardened, very strong) and used that as the pin. I am confident that it will not shear, it took me 10 minutes to saw a portion of the drill bit with a sharp hacksaw blade. use the round part of the bit, not the cutting end as the pin.

 

Good little tip. I'm sure many of us can do this with our aftermarket lightened pulley problems.

 

hey do you have the perin pulley? or the stock??

 

i have the perrin pulley now. i think it is also a good idea to run the perrin, zpi, or agency power pulley because that are aluminum and bite the crank better ( less stress on roll pin). oppose to the stock steal pulley that is

 

Using the part of the bit is not a good idea. Drill bits get weak when they get hot from spinning. Thats why the bits brake under pressure at high rpm on the drill. I would go to a hardware store and find a pin that would work, or go to an industrial metal place and see if they have something you can use.

 

i have at one point put a grade 8 pin in place of the stock one. Within a week it sheared. Alloy steel is the next strongest thing, but it's tensile strengh is not much more that grade 8. Case hardened alloy steel (drill bit)is almost as strong as Boron steel( strongest steel availible). So basicaly if the drill bit end doesnt work, nothing will. Believe me i know my materials, my good friend works with all the latest composites and metals, he's a scientific dude. Ill ask him his opinion the weekend to make sure.

 

Just make sure its a good bit. How are you securing the bit in place? Or are you just pressing it in?

 

What if the bit shears? I'd hate to try and get that out.

For the pulley, is a pin the only means of transferring power from the crank to the pulley? No keyway? Sorry for the questions, but at 500 miles, I have yet to pull anything apart on the xA.

 

so when it sheared you had the stock pully in or perin.. i am just about to install the perin in my car with the greddy but if your having this problem with it ill just keep the stock in.

 

Has ANYONE else had this problem or just you? That's not an attack, just curious.

Also, has it happend with the stock steel pulley at all to anyone?

 

Lastlookcustom's (Stu) had his pin break also. I'll see if I can find the thread.

Here's the thread. https://www.scionlife.com/forums/vie...asc&highlight=

 

i had the stock pulley on when it sheared last.

 

dammm stock.. now i have to go out side and check.. the only way you noticed was yu saw it lossing boost.. I better gets me a boost gauge.. what other way did you notice.. if there was any..

 

Hmm.. I'll have to investigate. Seems to me.. from what your saying this pin along with the tension from the crank bolt is all that is holding it on the shaft.. is this correct?

 

Another reason Im not a fan of supercharging. The superchargers are mechanically driven whereas turbos are driven from exhaust gas...fewer things to go mechanically wrong imo.

 

nice lookin out propz

 

update. Drove the crap outta my car this weekend, Drag raced and autocrossed. New pin held up fine

 

When my pin sheared, I noticed due to the loss in boost and the horrible sound the pulley was making as it wobbled on the end of the crank. At the time, I was running the Perrin pulley.

I replaced the sheared pin with another roll pin for the time being and drove the car home. The next day I noticed that the pulley was still wobbling. So I pulled off the pulley and noticed that when it wobbled the first time, I ate into the aluminum of the Perrin pulley so it never sat flush again.

I replaced the pin again with another steel roll pin (similiar to factory), nothing hardened or special, put on my FACTORY pulley and tightened the hell out of it.

So far, I havent had a problem. I have drag raced it, launched hard on the street and just normally drive the car very hard. I havent had a problem.

So dont anyone be afraid, just keep an eye on it and make sure its always tight....