just a note... how to use cotter pins the RIGHT way

I didn't think anyone needed to be told how to use cotter pins, but the last 3 suspension setups I've pulled apart drove me absolutely nuts, so apparently it's not commonly known information. To avoid cursing your past self, here's how you want to put a cotter pin in:

Another acceptable way:

No! noooo! not like that!:


Reason - after a few years, that hole the cotter pin is stuck in is going to be packed full of a combination of rust, road grime, and grease. The end of the pin that is bent out over the end of the shaft will have turned mostly to rust and will be very weak, but the part semi-hidden inside the notch in the castle nut will be at full strength. This makes bending the pin straight again to remove it fairly difficult... and once you have, how do you get it out? The loop on the other end of the pin is inside the notch in the castle nut. Let me tell you, on balljoints and TREs those can be a real party... especially when the blasted thing is so rusty that trying to simply turn the nut and shear the pin off with it results in the TRE ball spinning and many interesting words being applied to it :smsoap:

Not like this either! This is an accident looking for a place to happen!:


Reason - that nut can make about 3-4 full turns before it'll actually get caught and stopped by the cotter pin. Steering is really really floppy and your wheels will be going all over the place by that point. If you put something together and it ends up like this, it means you need a taller castle nut or you reamed the tapers on your knuckles out too deep.

When a cotter pin is inserted properly, the loop won't fit into the notch in the castle nut, and the ends will be splayed out around the castle nut or shaft instead of folded over the end of it. This makes it way easier to straighten back out, and if it's stuck you can grab the splayed ends and saw them in and out to rotate the pin in the hole till it breaks free a bit before straightening it out. Also makes the loop easier to grab. For some reason I see cotter pins put on the right way on almost every dana 30 outer shaft nut, but they're almost always misused on steering and balljoints.

</rant>

thanks for the refresher! now i just have to wait and see how much of a problem mine will give me when i tear into my build

kastein said:

I didn't think anyone needed to be told how to use cotter pins, but the last 3 suspension setups I've pulled apart drove me absolutely nuts, so apparently it's not commonly known information. To avoid cursing your past self, here's how you want to put a cotter pin in:
No! noooo! not like that!:

Reason - after a few years, that hole the cotter pin is stuck in is going to be packed full of a combination of rust, road grime, and grease. The end of the pin that is bent out over the end of the shaft will have turned mostly to rust and will be very weak, but the part semi-hidden inside the notch in the castle nut will be at full strength. This makes bending the pin straight again to remove it fairly difficult... and once you have, how do you get it out? The loop on the other end of the pin is inside the notch in the castle nut. Let me tell you, on balljoints and TREs those can be a real party... especially when the blasted thing is so rusty that trying to simply turn the nut and shear the pin off with it results in the TRE ball spinning and many interesting words being applied to it :smsoap:

</rant>

Click to expand...

There's nothing wrong with this one except the straight end hasn't been trimmed enough to put the dust cap back on if it has one. The method used depends on the specific fastener and it's application.

http://www.tpub.com/content/aviationmaintandmisc/TM-1-1500-204-23-6/css/TM-1-1500-204-23-6_87.htm

The "Alternate" showing on that page is the one I find works better... I see no reason why it would perform worse than the "preferred" method and like I said it is far, far easier to remove after the weather does its work. It can be nearly impossible to remove a corroded-in-place pin installed using the "preferred" method when the head of the pin has been drawn all the way into the slot in the castle nut.

This rant was mostly the result of me fighting with rusted in place cotter pins, your mileage may vary, if you like fighting with them more than I do, go ahead and bend them up over the end of the stud :dunno:

At first I thought, how can you use a cotter pin incorrectly. After seeing the picture I can see how that would be a huge pain to later remove. It seems like it would do the job needed just fine but removal would be horrible.

Little trick about cotter pins- they are never that hard to remove. If they're stuck just snip the ends off enough to get a socket on. The pin will shear off, remove the nut, knock the chunks out of the hole. I have never damaged threads this way.

JJacobs - yeah, works great, except when...

kastein said:

Let me tell you, on balljoints and TREs those can be a real party... especially when the blasted thing is so rusty that trying to simply turn the nut and shear the pin off with it results in the TRE ball spinning and many interesting words being applied to it :smsoap:

Click to expand...

I learned that one the tough way on a TRE a while ago. I practically had the vehicle jacked up by the tie rod and it was still spinning, and the worst part was that it wouldn't tighten down again either, so I couldn't even give the cotter pin another try. Ended up cutting the TRE stud off.

JJacobs said:

Little trick about cotter pins- they are never that hard to remove. If they're stuck just snip the ends off enough to get a socket on. The pin will shear off, remove the nut, knock the chunks out of the hole. I have never damaged threads this way.

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Only if the threaded shaft is fixed, If it is a TRE or other ball type joint the taper will usually break free and spin.

Nice rant Ken, I knew I liked you.

gambit4000s said:

Only if the threaded shaft is fixed, If it is a TRE or other ball type joint the taper will usually break free and spin.

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Not in my little world.

Well, I guess I'll make my 1000th on post an affirmation of something my dad taught me when I was 14...on my '64 Chevy...and I inherited the XJ from him. So indirectly...he got me this far!!

Thanks Pops. You always end up being right after all.

I have found that the best way to use a Cotter key is to simply don't. Wherever possible, use a safety pin (I've also seen them called "mechanic's pin") instead.

The problem with a Cotter is that it's not field-serviceable, they're only fit to be used once. I tend to use mechanic's pins only once as well, but you can use them twice if you have to (when I remove a mechanic's pin, I'll blackline it and it gets relegated to shop use - keeping parts together and suchlike for organisation.)

In the attached pic, the pin I'm talking about is at the centre left side, pretty much holding everything together as a set. Find them in CRES - it's not difficult to do (I've been able to get them all day long in CRES at the local hardware store for years.)

Yeah... I keep a couple 3-packs of stainless steel 1.5"x1/8" cotter pins in my glovebox and "oh s**t kit", at this point it's mostly in case I forget to buy some for a project and both my jeeps are down for the count but when I get the XJ into wheeling condition, it'll be for trail usage.

I wouldn't want to use a safety pin on a hub nut or steering components - everything else, they're definitely a good thing.

ParadiseXJ said:

Well, I guess I'll make my 1000th on post an affirmation of something my dad taught me when I was 14...on my '64 Chevy...and I inherited the XJ from him. So indirectly...he got me this far!!

Thanks Pops. You always end up being right after all.

Click to expand...

well........what the heck did he say?

Er...THIS is how to install a cotter pin!! Wrap it around the shaft...not the nut.

At work on our helicopters we do our cotter pins like that and they never fail us, but we have some gooey stuff we put on all nuts, bolts and cotter pins to keep water out and guys at work use it on their vehicles and it keeps everything out. For me doin cotter pins the "wrong way" has become habbit bc thats how we do them at work

make the cotter pin effective at doing whats it is supposed to and make it so you can get it out eventually. to each is own i myself like the first way of doing it since i can usually straighten the tail end out and pull it with an awl. dunno if thats the right word but a screwdriver with a sharp point

I guess the environment and what you expect to encounter when you take it out again must influence your choice, but most sources would show the second "nooooo not that way" as more or less the correct one, with the head firmly in the slot, the long leg bent over the top of the bolt, and the short leg, if possible, bent down over the nut. Some cotter pins are even made with an offset head to ensure that they go all the way into the slot. Whether that's the best way to do it on a Jeep part when you expect to find it and its nut seized and encrusted with rust is of course another matter. I do axle cotter pins sideways because, as the OP notes, it's easier to get them out, and in addition, the cotter pin goes through a nut cover which shares the retaining work.