ShadowTek Posted October 20, 2014 Share Posted October 20, 2014 I had a nut come off a tie rod that I installed about 1,000 miles ago. I'm certian that I torqued the nut to the FSM's spec, and I used a new cotter pin to finish. The nut seemed to have simply twisted off, shearing off the cotter pin. I think I used anti seize on the castle nut, so I'm assuming that I should not have done that. Would it be better to use some low strength tread lock instead to proctect the treads? Or should I use nothing at all? Link to comment Share on other sites More sharing options...
djratlif Posted October 20, 2014 Share Posted October 20, 2014 I always use never-seize on the threads myself, although I live in an area covered in salt half of the year. They usually rot together anyway and I have a hell of a time getting them off. If its falling off though I would apply some lok-tite. The thread locker usually helps keep the threads from corroding together as well from what I've seen. Link to comment Share on other sites More sharing options...
Precise1 Posted October 20, 2014 Share Posted October 20, 2014 It is not normal for a castle nut to shear its cotter pin and come free, so something else is going on. Make sure you have the right parts, tapers match, etc. Thread locker should not be needed, but I doubt a low/medium yield would hurt regardless. I have no idea of Switzerland salts roads or not, but if so, some sort of coating makes a lot of sense. B Link to comment Share on other sites More sharing options...
Elmo Posted October 23, 2014 Share Posted October 23, 2014 (edited) As our moderator said: It is not normal for a castle nut to shear its cotter pin and come free, so something else is going on. I worked as a millwright, and can tell you that it's a big deal for a castle nut to shear it's cotter pin. Something is applying a rotational torgue to that nut with enough force to shear the pin, and that should never happen. Even if the pin is undersized, and/or rusted, it will hold against normal loads. The application of Neversieze or Loctite will not affect the locking ability of the cotter pin. "Loctite" is an anerobic setting plastic that stays soft untill you keep oxygen away from it by assembling your fastener. Blue grade seems to have the torque release of the average lock washer. Red grade will tear your stud/bolt in half if you try to release it without heat. Be aware that if you use red grade, you must use heat (propane or acetalyne) to break the bond. We did a test with red grade on a 1/2" fastener, and sheared the bolt in half trying to remove the nut. The nut stayed locked to the stub of the bolt. One of the biggest benefits of loctite is that it is gap filling, and once set, it will not allow water/salt solution to penetrate the thread spaces of the fastener. Because it degrades with heat, it does not work on exhaust components. For those applications, we always used "Neversieze". It comes in different formulations to handle different degrees of heat. When working in the boiler room, I always used "Felpro" high temp nickle formulation (2400* f). The rest of the time, I used the regular grade "Bostic Neversieze". We tried "Coppercote" because it was cheaper, and found it didn't work nearly as well as the neversieze. If you are going to buy any of these products, DON'T CHEAP OUT and buy off brand. The cost savings are not worth the misery of a rusted solid fastener at the side of the trail. Edited October 23, 2014 by Elmo Link to comment Share on other sites More sharing options...
ShadowTek Posted October 26, 2014 Author Share Posted October 26, 2014 I finally got around to replacing the tie rod today, and I could get a better look at the old one. http://oi57.tinypic.com/bdta2x.jpg The bolt threads were mashed, and there was what looked like a piece of thread left from the nut wrapped around it. I guess that snapping off was when it went, then the flat threads allowed it to jump. The torque specs in the fsm say 40 to 70 ft lbs, so I probably put it at 70 ft lbs. It looks like that may have been to much for this aftermarket tie rod (Master Pro) to handle. Or maybe that's just too high of a torque regardless of what the fsm says. I didn't torque it down as tight this time, so hopefully it'll hold. Link to comment Share on other sites More sharing options...
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