Rod nuts


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By nonne_56 - 15 Years Ago
Hi

I put the pistons back in my 292 today, what do you guys say about the " looking nuts " the thin nuts on top of the real ones. In my mind these can do more harm than use. So, put them back or put them in the metal scrap bin, what have you done?

Nonne

By MoonShadow - 15 Years Ago
I would say use them. They serve a purpose as a lock nut or locking washer. Better would be to get a set of ARP Rod bolts but then you would have to have the rods checked out again. There may be a self locking alternate but one of the guru's here will have to speak to that. Chuck in NH
By oldcarmark - 15 Years Ago
I believe they were discontinued after 56.I never put mine back on.Cant hurt if you do put back on.
By MoonShadow - 15 Years Ago
I'm not sure if they used the same type nuts or an improved locking type on the later engines. Chuck in NH
By nonne_56 - 15 Years Ago
Thank's for your answers. I put them on first but i took them off again. When i pull the rods out some of them where loose, just need fingers to screw them off. That's why i ask about your thoughts. I know they are not used in later engines, mine is a 56.

Nonne

By marvh - 15 Years Ago
They are called PAL lock nuts. PAL is the mfg name.



Mr G has them http://www.mrgusa.com/pdfs/83-89palnut.pdf on pg 85

I always use them on any engine I build if there is enough room to install them I have seen the mess that can happen if a rod nut should come loose, not at all pretty. Always use new Pal nuts as they loose their spring tension after having been used. This very cheap insurance as the cost is between 8 -15 cents each nut



Most bolt hardware store carry them as they are still used on many engines.



You need the 3/8" X 24 tpi size. Torque the rod nuts until specification then install the PAL locking nuts. When installing the Pal locking nuts tighten by hand until contact is made then use a wrench to tighten an additional 1/4 -1/3 turn.



marv
By 314 - 15 Years Ago
trash them.their a thing of the past.
By Craig Seyfried - 15 Years Ago
You can throw them out or get new ones. If you don't use them a drop of BLUE LOCTITE on the rod bolt treads is some good insurance.

                                                             Andy of Mayberry

By NoShortcuts - 15 Years Ago
IF you do choose to use the Pal nuts, I agree with Marv:



1) Always use new Pal nuts as they lose their spring tension after having been used.



2) Torque the rod nuts to specification then install the PAL locking nuts. When installing the Pal locking nuts, tighten by hand until contact is made then use a wrench to tighten an additional 1/4 -1/3 turn. NOTE: The '56 Ford car Shop Manual says to torque them to 3-4 foot pounds.



The above said, I have had several individuals that rebuild engines for a living caution me on the possibility of a Pal nut coming loose. Like Andy, I've gone to using Blue Loctite No. 242 on the connecting rod threads instead of the Pal nuts. This seems like a modern alternative.



I hope that Ted, Tim, John and others will share their thoughts / experiences on this topic.



NoShortcuts
By Ted - 15 Years Ago
NoShortcuts (12/10/2010)
I hope that Ted, Tim, John and others will share their thoughts / experiences on this topic.

No Pal nuts used here.  Besides the fact that used Pal nuts should be replaced with new ones, there is always the possibility of them coming loose.  I have seen them laying loose in the oil pans so this is a real possibility.  With that being said, a properly stretched rod bolt will keep the rod nut in place without the use of Pal nuts or a chemical thread locker.  If it takes a Pal nut or thread locker to insure a rod nut does not come loose, the rest of the rod bolt fastening hardware is marginal at best.  ‘Marginal’ can occur where the bolts themselves have been torqued an excessive number of times or the bolts have experienced an extreme number of cycles.  In these instances the bolts and nuts are replaced as Pal nuts are poor insurance in maintaining integrity of a torqued rod bolt and nut assembly.

 

If you are intent on using the Pal nuts and plan on balancing the engine, then be sure to supply the new Pal nuts to the balancing shop with the rest of the parts being balanced.