Cracked intake plenum eyelet

[leathermaneod]

Hey all,

just looking for some ideas here. My truck has one of the cast iron eyelets, the ones on the head that the intake horn bolts screw into, broken off. It hasn't been a big deal because I have an aftermarket horn that uses studs and nuts instead of bolts. So I just have a nut on the other end, inside the intake plenum, with loctite to make sure it doesn't come off and get sucked in. I am about to take the intake horn off again to replace my powesteering pump and reseal my vacuum pump and I was wondering if I would be better off with a lock nut and loctite just as an extra safety to make sure that nut doesn't come off, but I'm not sure if that would be safe either because I'm not sure if the nylon ring could get sucked or fall out. I'm also concerned about the heat from the grid heater weakening the loctite or melting the nylon in a locknut. What do you all think? What would you do? I know the right answer is replace the head, but that's just not an option right now, so what's the next best thing?

Edited June 14, 2016 by leathermaneod

[TFaoro]

12 minutes ago, leathermaneod said:

Hey all,

just looking for some ideas here. My truck has one of the cast iron eyelets, the ones on the head that the intake horn bolts screw into, broken off. It hasn't been a big deal because I have an aftermarket horn that uses studs and nuts instead of bolts. So I just have a nut on the other end, inside the intake plenum, with loctite to make sure it doesn't come off and get sucked in. I am about to take the intake horn off again to replace my powesteering pump and reseal my vacuum pump and I was wondering if I would be better off with a lock nut and loctite just as an extra safety to make sure that nut doesn't come off, but I'm not sure if that would be safe either because I'm not sure if the nylon ring could get sucked or fall out. I'm also concerned about the heat from the grid heater weakening the loctite or melting the nylon in a locknut. What do you all think? What would you do? I know the right answer is replace the head, but that's just not an option right now, so what's the next best thing?

I wouldn't worry about replacing the head.

I would not use a nylon locknut because of the heat. It could melt then come out.

Personally, I would use a regular nut with high temp permanent Loctite, or a thread deforming locknut with high temp Loctite.

[leathermaneod]

Thanks for the reply! Do you think the regular red hi temp loctite is good or is there something better out there I could use? Not sure if the hi temp red is as strong as the regular red? What is a thread deforming lock nut? Something I could find at a Fastenal?

[IBMobile]

Deforming lock nut also known as a pinch nut

 

Edited June 14, 2016 by IBMobile

[leathermaneod]

Is a deforming lock nut removable? Any recomendations on a specific loc tite to use?

[TFaoro]

At least this: http://www.criticaltool.com/loctite-272-high-temperature-high-strength-red-threadlocker

 

Fastenal calls it a top lock nut  

https://www.fastenal.com/products/fasteners/nuts/lock-nuts?r=~|categoryl1:"600000 Fasteners"|~ ~|categoryl2:"600072 Nuts"|~ ~|categoryl3:"600081 Lock Nuts"|~ ~|sattr02:^Steel$|~ ~|sattr03:^"Top Lock Nut"$|~

 

Paste ^^^ whole thing into the url bar

[IBMobile]

You can take them off with no problem but they will not lock again if reused.

[leathermaneod]

Cool. Thank you guys very much this was super helpful! Now I won't have to worry about that darn thing anymore. Only bad thing left is that I have to keep it from spinning while tightening the nut down on the other end outside of the horn. I don't think there's any way to prevent that though.

[Haggar]

Leather,

 

I can't picture which one is broken, but you could weld a "wing" to the nut?  This would allow it to swing and stop providing the resisting torque.  Like the blind nut on the track bar.

 

HTH

Hag

[leathermaneod]

I'll take a pic for you when I have it apart this weekend. I don't remember for sure if it would work, but your idea definitely sounds like a good one.  Only problem for me is, I don't have a welder where I live right now. I just picked up one of those top lock nuts though and I'm about to order some loctite 272 to take care of it for now. I always wanted to just tack weld a spot on the nut so it couldn't separate, but again the problem of not having a welder. If i every have things apart while I'm at my parents or in-laws, or when I'm out of the Army, I'll try your idea. 

[Royal Squire]

You can actually make a lock nut by just whacking the side of the nut with a hammer. May take a little practice so you don't smash it too far, if nut will easily spin onto bolt, then you need to give it a little more, if you can't get nut started onto bolt then you need a new nut. 

[leathermaneod]

Thanks for All the input guys! Only issue with the top lock nut is I can't screw the nut on very far, but hopefully I can get enough for it to bite. 

[Mopar1973Man]

Some how I would be looking for a good machinist to create a but repair. The fact of always removing the intake horn all the time the last thing I would want to do is constant fight with a specialty nut to hold the air horn on. I would see if any one would have the ability of repair for this.

[leathermaneod]

Yes that would be ideal. Fortunately though, I don't take my intake horn off very much, and even so, this nut should be a one time thing. It doesn't have to be removed every time. Only way you would need to remove it is if the stud had to come out. 

[leathermaneod]

Got another question about my upcoming job. I've been reading everything i can about the vacuum pump reseal and some guys are saying to keep the shaft seal dry, and others are saying to lube everything. I always think it's best to lube the seals, but I've been wrong before. Is there a need to keep any of the seals dry when rebuilding the vac pump?

[TFaoro]

If you bought it from Cummins and it says dry, you should put it in dry. I believe mine said dry, and I was able to push it in with my thumbs.

[leathermaneod]

I bought it on eBay because it had free shipping and my local Cummins place wanted $10 for freight, but it should be a Cummins part. So, if it comes with instructions, I'll follow them. Thanks!

[notlimah]

Here's some other options

 

http://www.mcmaster.com/#hex-locknuts/=12uvbyk

[leathermaneod]

Hint one more question on the loctite. Just got the 272 stuff in the mail. I was reading the package and it says to use Loctite Klean an Prime Activator. I've never heard of that before. Do you guys think it's really necessary for this?? Or will I be ok just making sure the threads are clean before applying? 

[TFaoro]

I just spray the threads with starting fluid and blow it off with an air compressor. Haven't had any issues yet!