How to put a replacement TC sprocket on if it has a broached key?

[CatmanDobbins]

Hi everybody.

I've been trying to figure out the best setup for my go kart. It has #35 chain but I need a 10 tooth sprocket (or less than ten if they make them haha) on the torque converter in order to get the torque I need.


My problem is that most of the ones that I have looked at for 10T #35 have a key broached into the sprocket and not a keyway. E.G. http://www.bmikarts.com/TAV-Replace...JFCTfsUSRHMmgw4lmlWoA_5CC3Pc2lGRoCiXIQAvD_BwE

How would I mount it if it doesn't have a keyway?

In the video below the guy has to put a washer with a keyway into place on the driven side of the TC and immediately after that he puts on the torque converter. If there were no washer there then I could just cut the key to size since I wouldn't need it for the sprocket (again, since it is keyed itself). But since there is a washer there I would need a piece of key the width of the washer to hold it in place, which would be a total pain to figure out.

Anyone have any better ideas? Is there a reason that that washer has a keyway or can it just be free floating there?


https://www.youtube.com/watch?v=UK7EW9vcqSw

Thanks

 

[mckutzy]

I'm not sure I understand... A broach is used to cut a internal keyway??

 

[CatmanDobbins]

I'm not sure I understand... A broach is used to cut a internal keyway??

It's like this: https://www.ebay.com/i/162034705440?chn=ps&dispItem=1

Instead of this: https://www.jackssmallengines.com/j...qv4iwjf3tndrdu7bmv6euws47ezvz8lroctwqqavd_bwe

The key is basically on the sprocket itself so it doesn't have a keyway. It would require me to cut the piece of key that comes with the TC if I were to use it. The second link would have worked fine but I need #35.

 

[Whitetrashrocker]

Just cut the key way down to fit inside the TC. It's the shaft that transfers power not the key way.

Put a washer against the back plate(not sure why that one has a key slot),then your sprocket with the premade key. Then put your tc on with the key supplied. See how far it hangs out? Mark it and then cut it down a little shorter than your mark. That way the nut will not bind on the key before it gets to the proper tention.

 

[mckutzy]

Ahh I see... An integral key(and broached to form it)...

And yes... The key transfers force to the mounted item from the driving shaft via the keyway in the shaft.. (Otherwise on my few occasions of brake failures wouldn't have occured via a lost key)

 

[CatmanDobbins]

Just cut the key way down to fit inside the TC. It's the shaft that transfers power not the key way.

Put a washer against the back plate(not sure why that one has a key slot),then your sprocket with the premade key. Then put your tc on with the key supplied. See how far it hangs out? Mark it and then cut it down a little shorter than your mark. That way the nut will not bind on the key before it gets to the proper tention.

Very useful info thank you! If the washer does not need to have a key slot then my problem is solved. I'll make sure to cut the key down to the same length as it would be if it was all the way in so it all lines up the way it should be. Thanks again

 

[mckutzy]

If you want a #35,10t c type with a 5/8 bore.... Ask any local bearing supplier( I can't suggest a local to you as you don't list your location) as they will mostlikely have it, I had bought a similar one with 1/2" bore, it cost me $10