joerg65

I’m just in the middle of a valve adjustment and thought I’d measure the rocker play (side to side on the rocker shaft). All measure around 0.45mm which is at the upper end of free play. I don’t have any oil leaks but I have a reasonable amount of what appears to be rocker related tapping+thacking sounds.
I can’t find any other cause for the noises - I’ve checked the valve springs, head studs, rocker nuts and they are all fine. I can’t really check the torqued tightness of the hex ends of the rocker shaft but they seem pretty tight just by testing with Allen keys.
Any advice? Should I be concerned? What has worn to create the excessive free play and what’s the fix?

Metal Guru

If you had an issue with the shafts walking around (common in cars that have had the shafts removed more than once; some after one removal), you would have probably found at least one out-of-position.
Turbokraft in Arizona used to sell this https://parts.turbokraft.com/product...nt=18360163393 but it's not been available for a while now.
I wonder if you are hearing normal tappet noise.
You could try to set the clearance to the low end of the spec and see if that resolves your issue.
I'm set to the nominal clearance and have accepted that tappet noise is part of the air cooled charm along with the cooling fan whine.

tjb616

I'd love to hear more about this issue if anyone has literature (how to measure, max free play, etc.) When I did my first (first myself, second after break in) adjustment after a full rebuild I couldn't get a consistent reading because it varied with L/R play. Couldn't find any good info at the time so ended up using front+back feeler gauges. Didn't know there was a max allowable lateral play measurement at the time.

Video of my issue:

964Luftballoon

Thanks for sharing this. I had one of my rocker shaft bolts walk out on me. Wasn't a fun time trying to troubleshoot before ultimately looking down my valve cover and find one end of the bolt (replaced spark plug wires as part of troubleshooting process)