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Discussion Starter · #1 ·
I noticed that many of the rocker arm nuts (has solid lifters- 1.9 engine) were very easy to turn......i've replaced those with some off another engine......but, those don't seem all THAT "tight" either, but they are better. I no longer have any that are only slightly harder than finger turnable but I'm not sure how tight they have to be to keep them from loosening on their own. Is there a torque number that I could use to determine when these nuts are no longer usable.....or a way to keep them from loosening...i.e. a lock-nut?

Any info appreciated.
 

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Opel fan
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I had a 70 that used to do that, I put the ends of the nut in a vice and put enough pressure on them to make the end of the nut slightly oblong, that kept them from loosening up again. I don't know if this is a very good solution but it lasted long enough to make it to the next maintenance of valve adjustment with out loosening and causing tapping. HTH
 

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Jim, that's a very good fix on the self-locking nuts. Standard rule of thumb from the USAF Technical Order 1-1A-8, hardware manual, is if you can run a nut or a bolt past the self- locking feature by hand, it is time for a replacement. Generally, finger tight is about 15 inch pounds torque, so using that premise anything over 15 in.lb. is a good nut. The only real problem is getting the nut too flattened that it starts eating the threads of the bolt or stud. Finesse is the key word here. HTH.

Ron
 

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Try this: 1) put the nuts on a old bolt, 2) get a heavy point chisel, 3) hit the punch on all 6 faces of the nut & 4) vice the bolt and wrench the nut off. If this dosn't work for you, you may have to get a new set of nuts, maybe the split-top pressure nut types.
 

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I tried this on my first 1.9(72 Manta Raylle). I put another nut on top of the rocker nut and tightened them against each other. It locked them together and it never looseded in 10K miles(had to sell it because I got a 74 Manta Luxus).
 

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Opel Guy
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Does anyone know what thread the rocker studs are? My rocker arms come loose frequently too. I just purchased some locking nuts for a machine at work that the Nyloc nuts were loosening often. These nuts have a couple deformed threads and hold very well. They don't damage the screw thread either. If I can find the new nut for the 1.9, I'll let you know.
 

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Opel Guy
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The nut I was hoping to buy isn't available in 1mm pitch. The std course thread is 1.5mm pitch. I have a local fastener house looking for non-Nyloc nuts. Let ya know.
 
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