Originally Posted by onehundred80
Let me start by saying I have not held a SC pulley in my hand, but I do know about machining and machined parts and how to check them after making and designing them for fifty odd years. I do have a SC pulley but I am not about to take it off and look at it. Having said that you can quit reading right now or read on, your choice. I really do not care.
The experts here should know what I am about to say.
The SC pulley assembly consists of the following parts; pulley, spring, clutch plate, bearing and retainer, rivets, and drive pins.
The gap between the clutch plate and the SC face should be between 0,20 and 0,30mm or .008" and .012". I always think Americans and metric do not mix, it must be in the genes.
The back plate of the pulley has to be square to the axis of the bearings, any error there and the gap is going to be larger and smaller on the diametrically opposite sides of the clutch plate.
The spring has to riveted to the pulley and clutch plate, centrally located and with the rivets free of excessive play in the rivet holes. If the spring is out of center and the clutch plate is forced against the pins the spring will tend to tilt the clutch plate. The spring must lay flat in the relaxed position.
The clutch plate has to be located on the pulley centrally via the spring, as any offset will have it binding against the drive pins. This can only be done with accurately located and tight rivet holes in the pulley and clutch. Some error is expected but not enough to cause binding greater than the spring can overcome.
The drive pins mounted in the clutch plate should have a minimal clearance in the pulley back plate holes and the spring should not bias it in one direction or the pins will bind. The holes for the pins should be accurately located in both parts to the spring holes and bores.
When checking the 008"- 012" clearance and finding a discrepancy from one side to another, check to see if the distance between the front face of the clutch plate and the pulley plate is out by the same amount. If not it would indicate that the pulley is not square to the bearing bore. This assumes that the clutch plate is an even thickness.
Before installing the pulley check to see that the clutch plate is parallel to the back plate of the pulley, if not the spring is biasing the clutch plate, too much and the correct settings will be hard to obtain.
Assuming that the main components are machined accurately within good tolerances the problems could be caused by the riveting. If the spring is not accurately located and there is binding on the pins the set up will be impossible to do accurately. You do not want to run this when there is rubbing of the clutch plate when not engaged. It may free up after a while but the faces will no longer be flat due to wear, maybe no big deal in the long run it depends on the degree, but it will not be a 100% engagement when energized and may lead to further slippage and wear.
Shoot my theory down if you find an error, or two or .....
This thread has gone around and around with little said and some of it does not hold water.
You do realize that these are all new eurocharge code 3 style pulleys?