Lubricant for Pin Drive spinner

[Cobra #3170]

Originally Posted by Rick Parker

CHECK your NUTS:

Most of the 5 pin adapters utilize OEM 1/2" studs, but I believe the 6 pin setup on all the CSX cars and others actually are secured by 3/8 SAE nuts on the part of the stud that anchors in the wheel flange.


This is a unique 6 pin setup:


By the way the rotor was for the LR.

The CSX cars have the .5" pins recessed into the hub so that the pin is in shear the 3/8 " threaded portion and nut hold the pin in position so that the shear load is through the .5" portion of the pin.

[ACademic]

Originally Posted by Cobra #3170

It is the design of the 5 pin set up that is the problem not the number. at least the ones I have seen. On the technical side more fasteners are almost always better unless the number of holes weaken the parent structure. Formula Atlantics back in the Cosworth days had 12 flywheel bolts because of vibrational issues on a very small crank end flange. Aircraft design uses many small fasteners instead of a smaller number of large fasteners, heavy duty trucks use 6 bolt hubs, NASCAR is using lots of designs from the early days which are clearly outdated but they want to keep things "inexpensive". I haven't done the math but I would bet that (6) 1/2 fasteners in shear would have a higher failure load than (5) 5/8" fasteners. On the other side of the issue it is harder to get more fasteners to pick up the load in unison.

Originally Posted by Cobra #3170

The CSX cars have the .5" pins recessed into the hub so that the pin is in shear the 3/8 " threaded portion and nut hold the pin in position so that the shear load is through the .5" portion of the pin.

Cobra #3170, an EXCELLENT set of responses. Thank you very much.