Rocker Arms adjustment


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By Town Vicky - 11 Years Ago
I rebuilt a 292 that I got with my 59 Ranchero it had rebuilt rocker shafts but the adjustment screw turn too easy and they will not stay in adjustment what is a good fix?
Thank You Town Vicky
By slick56 - 11 Years Ago
Oversize-thread adjusters are available, i think they are 3 thou up. They have a 7/16 hex.

Try the Thunderbird supply houses, maybe someone will chime in with where to get them.

If no luck, you could go to the early style adjuster with locknut; i'm sure someone here will
have a set to donate..
.
By lyonroad - 11 Years Ago
Ted went round and round this issue about a year or so ago.  I don't know how to post a link to that thread but hear is what he said.

"Ford used two different thread designs for the rockers. Both are 20 tpi but the thread cut is different. The early adjusters (1954-1956) using the jam or locking nuts is a conventional 7/16 X 20 cut while the 1957 and newer rockers used a friction style of adjuster that required an interference thread design to keep the adjuster tight without the use of a jam nut. To use an early adjuster stud and jam nut combination in the later model rocker, simply re-tap the threaded hole with a conventional 7/16 X 20 tap to clear out the interference threads. It may be necessary to machine a flat on the top of the later model rocker so that the jam nut will tighten squarely on the rocker. I suspect that a TSB regarding this would have gone into more detail than to say to simply replace the adjusters from one style to another."

If you can access the thread there is more information available.  I found it by scrolling through Ted's replies.  I found this on page 10 or 11 I think.
 
I also seem to recall that the adjusters with oversized threads are actually a FE adjuster and the ball is slightly larger than that of the Y adjuster screw.
 
I hope this helps.
 
      
By Ted - 11 Years Ago

Here’s the link to the thread mentioned above.
http://forums.y-blocksforever.com/FindPost98395.aspx


There are several fixes for the loose interference thread adjusters.  Here are just a few of them.

  1. Thoroughly clean the threads and use Loctite.
  2. Using the 0.002” oversize adjusters if you can find them.
  3. Drilling and tapping the sides of the adjusters for either 8-32 or 10-32 set screws that can be tightened into the loose adjusters.
  4. Retreading the rockers for a conventional 7/16-20 thread and using the early non-interference thread adjuster screws and jam nuts.  You may have to grind or machine a flat on top of the adjuster for the jam nuts.  (This is the one I prefer)