is it necessary to have the top surface of the flat top knuckles machined when preparing them for high steer arms? or can I get away with some grinding/sanding to smooth things out?

I know drilling and tapping is required for the arms, but i hadn't heard anything about machine work in my research til i came across one article that said you needed this to keep the clamping forces on the studs even and maximized.

Is this necessary or overkill?

-Rob

bob roggy and others say it's a must ... other say they've never done and don't have a problem. some say they've gotten the knuckles flat with a hand file ... must have taken a while is my thought. personally, i'd get them milled flat before i drilled them.

- jack

Originally posted by morpheus
bob roggy and others say it's a must ... other say they've never done and don't have a problem. some say they've gotten the knuckles flat with a hand file ... must have taken a while is my thought. personally, i'd get them milled flat before i drilled them.

- jack

I second that...

how much you think it would run me to have my passenger side knuckle milled flat and drilled and tapped for the studs if i took it to a local machine shop?

Dallas

in order to maximinze the strenght of the "joint" the mating surfaces of the steering arm and the knuckle must be machined flat.

I used a fly cutter on a bridgeport mill, it took a few passess, the material is pretty soft, it was easy mill, and drill.

Originally posted by StinkBug
how much you think it would run me to have my passenger side knuckle milled flat and drilled and tapped for the studs if i took it to a local machine shop?

Dallas
I had one milled drilled and tapped for $25. Since I am nowhere near your local machine shop, I have no idea. Why don't you call them and find out:question:

The whole premise behind the flat surface has to do with frictional forces. If done correctly, the 3 studs should see little to no shear force. They are just there to provide the necessary clamping force to allow the friction between the arm and the knuckle to overcome the shearing forces generated by the the steering. The cone washers on the studs provide for an extremely tight clearance between the arm and the studs so that there is no slop and thereby reducing if not eliminating the shear force placed on the studs. Bottom line.... mill the knuckle.

Sorry to bring up such an old thread, but I have a question I could not find the answer to and this was the closest I could find. I purchased some high steer arms from Poisen Spyder and noticed they have a keyway where it is supposed to mate to the knuckle. I know they have that there in case a spacer is needed but that is not needed in my case. Should I have the keyway machined out?

the obvious answer is for you to call the manufacturer of the arm and ask them how they intended for them to be mated to the knuckle......

That is a great idea except it is poisen spyder and the last time I had a tech question for them they gave me a pretty stupid answer regaurding another part. With that said, I think the products are great, but the customer service communication skills are on the same level as a McDonalds cashier. I went so far as to buy from a 3rd party this time as not to have to deal with them. The question just dawned on me today so I did not want to wait until Monday to get opnions. I'm pretty sure I will have the arms milled, I just want to know if it is o.k. if I don't, an why that would be.

I used a file, didn't take too long. Still works great at 3 years old. Use studs, not bolts.