Datsun Roadster Forum-311s.org

I got a rebuilt idler box with new vertical shaft and bushings, etc assembled. The idler arm and external seal was not assembled. I am about to assemble and install on the vehicle, but here is my question:

Since the vertical shaft threads in from the top, how much length of shaft should be sticking out the bottom of the box so that when the arm is installed and the seal is on, there is the proper pre-load on the seal during full left-to-right rotation in use?

Thanks

I don't recall ever seeing any sort of measurement. I threaded the shaft into the idler box, counting the number of revolutions, divided that by 1/2 and that's pretty much how mine was done.
Probably not "right" but seems to be fine.
Consider that, when in use, the shaft does not make a full revolution so the amount of vertical movement in the idler shaft is less than 1 thread pitch. The seal is pretty compressible so I'd think if you're off a few turns, its likely fine.
Dan

Thanks for the response. I'm going to be assembling tonight and I'll see how the fit-up with the seal goes based on your method. It didn't seem like there was a precision process noted anywhere, so I figured that I'd ask.