im gonna be replacing a idler pulley lock nut in a couple days. they are 14mm i believe. What is the thread size on the nut? Will M12-1.75 be a good fit? thanks

 

If it's a 14mm nut, it is unlikely the thread is 12mm. That leaves only 1mm for the walls which is less than 1/32". 10mm fine thread sounds more likely. You need a flanged high-strength nut, so if possible, take the original one to an industrial fastener place, or to the dealer.

 

I dont know much about matching thread sizes and nut sizes. But, replacement pulleys have a bearing diameter of 12mm. Doesnt that mean a m12 1.75 thread size torque nut works? Plz correct me if im wrong. Thanks.

 

I was just going off common sense which raised a flag. Should not the thread be smaller diameter than the shaft?

You should be able to get the correct size from the FSM. Download a copy!

 

Im gonna look deeper into the fsm. I glanced at it but couldnt find info on the nut. But i will look closer. If not, ill give the local nissan dealer a call.

 

Just replaced one last week. It is an M10-1.25 flat faced flange nut. You won't find it at your local hardware store but you should be able to get one from a decent auto store, I found mine at Canadian Tire and I think it was a pack of 4.

If it's rounded, get yourself a 14mm Grip-Tite wrench and save yourself considerable frustration, you're not getting a socket in there...

 

yea, the common sense came to me earlier when i was talking with my cousin about the thread in spark plugs. Your comment made so much more sense. haha. seems it is a 10mm based on the previous reply.

Thank you.

 

This is what car forums are for, glad to help!