Doing a ground up rebuild. My half shafts looked good and operated smoothly, but decided to rebuild them since they are 43 years old. Now that they are cleaned, with new grease they won't slide at all. Is this a concern, or will they break in once back on the car? Thanks for your help, Kevin.

That would be a concern. I rebuilt one that was binding, just to see if I could and when I was done, it moved more freely. I have a collection of used ones and they all slide freely, except for the force required to move the rubber boot.

I agree with Zed that this is a concern. I rebuilt both of mine and they slid freely (albeit with some force) and smoothly.

Did you get the balls and spacers back in the right order and did you ensure that they stayed in the grooves? I found this pretty tricky and a few of them went in a little hard, but once the shaft was all the way in, everything moved as expected.

I have pictures of my install if that will help. Just let me know and I will post a couple.

Mike.

I felt confident about the rebuild. I had a good blow up diagram. The mechanics are pretty straight forward. I was just thinking that with all new grease it might take some stronger force than I can generate to get everything moving and broken in.

I have to compress mine a small amount to get them in on my 280Z. If you can't move them at all by hand you won't be able to install them.