Removing Roll Pins

I just had to replace the spring on a trailer jack. This is the spring that snaps the lock lever into the hole on the frame to lock the jack in place, either down for jacking, or up for hauling. I thought this would be simple. I had an old drum brake spring that was almost the same size, so all I had to do was remove the roll pin, replace the spring and put the roll pin back.

WRONG..... This turned out to be a nightmare of a job. The roll pin would not come out. I'm sure it was rusty, so I soaked it with PB Blaster. I hammered on it with a punch, and it got a flat end, meaning it would not pass thru the hole. But I figured I'd hammer it loose and then remove it from the other side. Instead, it broke off. I went to the other side and broke that side too. I took my grinder and flattened the end of the pin to remove the spring and the whole thing from the jack. I placed the part in my vice and hammered for a half hour, and it would not budge. Now this is just a

1/8" roll pin, nothing large, so common sense says it should have come out by hammering.

I placed the part in my drill press and decided to drill it out. I applied PB Blaster as a cutting oil and began drilling. The bit penetrated less than 1/32 of an inch before the drill bit just turned red and shattered. What ever metal those roll pins are made of, is extremely hard. I got another bit, and a minute later the tip of the bit was flat, and I had only gone in another 1/32 of an inch. Teo more bits and I was a little more than halfway thru the 1/2" thick piece of steel. I found a slightly larger bit, and one that was a top quality bit. That one threw sparks, but kept biting in, very slowly.

90% of the way thru the 1/2" shaft, that bit broke. I did not have any more bits that would fit. I finally took the broken piece of the bit and applied as much pressure on the drill press handle as I could. About the time the bit was glowing red, it broke thru. Total time spent drilling - almost 3 hours. Total time on entire job, 4 hours 20 min. Plus $10 to $15 worth of drill bits. (Next time I'll replace the jack).

How in the hell are roll pins supposed to be removed? No matter what you do, they are going to flatten on the end, and of course then they dont come out. I'm sure my rusty one did not help, but still, it should have come out easier than it did.

The rest of the job was easy. I installed the new spring, and replaced the roll pin with a cotter pin rather than another roll pin. Cotter pins come out much easier and can be drilled out with any bit if needed. If I never see another roll pin, it will be a good thing.

Reply to
barleypop5
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Any chance the roll pin was bent? They are spring steel. Hard and tough, as you know:)

Al

Reply to
Big Al

There are roll pin punches designed for this purpose. Like Al says, roll pins -- especially the higher-quality types -- are hard and tough. Like spring steel, almost (high carbon steel, methinks). If the roll pin is rusted, seized, or otherwise immobilized, even a roll pin punch might not work.

Look for another thread on alt.home.repair with the subject "Extracting broken bolt / screw" in which I ramble on about how to remove a broken bolt with an oxy-acetylene cutting torch, even if you don't know how to weld. You could apply the same technique to frozen roll pins.

The roll pin punch is basically the same as a pin punch or drift, but with a rounded convex "bump" to help keep the punch more or less centered in the roll pin. Below is a crude "usenet art" diagram of the punching end, not the hammering end (to the right of the diagram), of a roll pin punch. Visualize the solid punching end of a pin punch:

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Reply to
maxodyne

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I used to fix a machine that used roll pins that customer abuse could break but worse bend:(:(

often I replaced assemblies cause the pin couldnt be removed. frankly i have hated roll pins ever since.

they rate right up there with allen screws some jerk tightens till the wrench goes click click cl;ick:(

If you have something that uses roll pins its a good idea to give it a shot of oil on a regular basis

Reply to
hallerb

Describe the pin. Is it a roll pin or a split pin?

Reply to
tnom

I have learned a few things about these situations. Pressing is often more effective than driving. Driving on the end of a tight press screw can help. If you are going to drive it with a hammer and it is really tight, don't play around with it. Get the biggest punch that can fit and the biggest hammer you can swing well. Hold the punch well centered and well in line. As my Dad used to say, "Hit it like you mean it". Don't try to tap it out with many small blows as that is what mushrooms the end. Another important point often overlooked is to be sure you have the stationary part well supported close to the work area. Any springiness, which all metal has, will work to lessen the effect of your hammer. If nothing else, have a helper hold a heavy axe or hammer tightly against the back side. You have to use inertia to your benefit.

Don Young

Reply to
Don Young

Thanks! I've wondered for YEARS what the heck some "donated" tools I picked up were for!

Reply to
Twayne

What's a split pin? I looked up "roll pin" on google, went to images. It's a roll pin !!!!

Repeat: What's a split pin?

Reply to
barleypop5

AKA cotter pin.

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Reply to
maxodyne

You should have used a regular roll pin punch. The best ones are made by Mayhew. You'll find them at SnapOn, Mac, Matco, Grainger, McMaster, places like that. Most sets you buy will will last a lifetime, so don't sweat the price. I have some in my tool box that have survived three decades of use in a busy repair shop. Your technique for removal was all brute force and awkwardness. Here's how to do it right:: first soak in penetrant, insert proper Mayhew punch , tap firmly. If no go, repeat. If still no go, don't fool with it, get out the torch, bring the parts to a dull red heat, cool and soak with penetrant and the roll pin will tap right out. Replace with a new roll pin, same size or next size larger, resizing hole if needed for press fit. Using anything else but a roll pin is foolish, because it supplies considerable strength to the pivot area where installed. Using a cotter pin or a bent nail is only asking for future trouble. HTH

Joe

Reply to
Joe

kinds, I am aware of two distinctly different types of "roll pins". The most common type is made of relatively heavy spring steel formed in a partial circle with a lengthwise slot. The other one is made of several turns of relatively thin spring steel without any slot, kinda like a short wide clock spring wound up real tight. The first squeezes the slot narrower when compressed and the second rolls the layers around themselves.

Don Young

Reply to
Don Young

Oh, a cotter pin. Why didn't he just say that? That's what I used to replace the roll pin, and it worked just as well for this situation. Cotter pins are not as hard to remove and if they need to be drilled out, they are a soft metal.

The roll pin I dealt with was the first one you said. The one with the lengthwise split in the side. And I sure found out how hard that steel is, by destroying 4 drill bits. I still cant believe that I was able to finish the job with a broken off bit with no tip on it. By that time I was so fed up with the whole job, I just burned it thru the last 1/16 inch or so. The remaining piece of the bit was glowing red when I finished.

Reply to
barleypop5

snipped-for-privacy@unlisted.com wrote: ...

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There was a reason for using a roll pin in the original -- probably specifically for that hardness. Substituting a cotter is likely not a good idea.

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Reply to
dpb

The drills break because of the split in the pin catching the bit and torquing it. Backing-up (as suggested) is a good idea. We used a "bucking bar", a slotted long heavy bar on the opposite side to increase the blow of the hammer. The key is a helper: one backs-up (or holds unit in a vise); and one strikes the blow (and it needs to be a good one!)

There are also tapered pins that have to be broached (if used in a new application) to taper both shaft and arm.

Many, many years ago I worked on mechanical NCR cash registers.

Reply to
pheeh.zero

Depending on the semantics........

All these pins are spring pins. There are two types made.

A slotted spring pin commonly called a split pin or roll pin

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A coiled spring pin commonly called a roll pin
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Reply to
tnom

Since when has anybody called a cotter pin a split pin?

Reply to
tnom

I've heard them called that. I think it's a regional thing... Like creek or stream? river or bayou? What I would call a creek, my relatives in North Carolina call a branch. Or "brainche", as they pronounce it. "Cotter" sounds like someone's last name to me. If so, then Cotter's "pin" resembled a pin that had been "split". Dunno.

All Kleenexes are tissues, but not all tissues are Kleenexes. More or less.

Perhaps the real answer is lost to antiquity. Anyone know the origin of the "Cotter" pin?

Reply to
maxodyne

Point well taken. Pin hardness can be a specification. Some applications require a roll pin, tapered pin, or splined pin (hardness optional) because the pin must be flush i.e. no part of the pin may project beyond the hole it is in. If that didn't matter, then perhaps a Cotter pin could substitute for a roll pin.

Reply to
maxodyne

Far more likely problem would be the shear strength.

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Reply to
dpb

True, although cotter pins can be used just to secure something where shear forces are handled elsewhere. As in an old automotive non-driven wheel bearing application: the wheel bearings support the axle weight (major shear force), an axle nut keeps the bearings in adjustment (minor compressive force), and the Cotter pin merely serves to keep the nut from moving (minimal compressive force).

Reply to
maxodyne

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