Removing Wrist Pin Clip
 

How do you remove the spring clip that retains the wrist pin in this piston? It is item 5 in the attached exploded diagram. It is in a grove in the piston, circular and with a 1/8 inch gap. There is a channel in the piston that leads to the bottom of the clip. A jeweler’s screw diver can fit between the clip and the body of the piston. The ring can not be rotated in the groove and its gap is not facing the channel. Prying it out with a screw driver may do it but I doubt if the ring will be reusable. Any ideas? Dan.

RE: Removing Wrist Pin Clip
 

That's exactly how you take them out; by compressing them and prying them out using that groove. It is not recommended to re-use the circlips, ever. (Though a lot of people do and get away with it.)

Sometimes when the clip is taken out, a small amount of aluminum is raised where the clip came out, or where perhaps your tool gouges it. Look closely and clean up the area carefully with an exacto knife so that the wrist pin slides out without interference.

Also, when installing a circlip, the gap should face up towards the head, or down towards the crankcase; not sideways.

AV8TOR

RE: Removing Wrist Pin Clip
 

If you do re-use the circlip, they can get deformed when removing, you may need to expand it gentlly before installing so it will seat snugly in the retaining groove.

RE: Removing Wrist Pin Clip
 

Thanks you two. I'm heading in the right direction. I just don't like using brute force around aluminum parts. Av8tor. I can't see how it is possible to compress the clip ring while I'm pushing a small screw driver under it. It's just an open circle with no loops on the ends. Dan.

RE: Removing Wrist Pin Clip
 

Dan, I just had to do the same thing on a Rossi .45. Man that little clip was only .0012 dia. I was able to use the tip of an x-acto #11 blade to catch the end of the clip and compress/lift at the same time. Took much longer to get the clip back into the new piston.

RE: Removing Wrist Pin Clip
 

If you push hard enough on the circlip right where that groove in the piston allows you to push on it, the circlip will compress enough that you can get the screwdriver under/behind it and walk the clip out. Trust me, it works....

That's why that groove is there. Just don't slip and poke a hole in your other hand holding the piston. (Wanna guess how I know that?) ;)

AV8TOR

RE: Removing Wrist Pin Clip
 

Walla! It worked! If a little force does not do it, then try some more. I got the ring out by prying a small screwdriver blade under the ring at the channel in the piston. With a mighty twist the ring came out. Reusing it was not an issue because it flew out into that bottomless pit called the floor. Thanks guys for the inputs. Dan.

RE: Removing Wrist Pin Clip
 

Oh my bad , I almost added in my post to do the clip removal within a box that is set on its edge to catch the clip. Sorry

RE: Removing Wrist Pin Clip
 

Next time. Dan

RE: Removing Wrist Pin Clip
 

We call this and other hard to work with circlips "Jesus Clips". That's because they often fly away to "never never land", and when they do you go "OH JESUS!!", "I'LL NEVER FIND IT!!"

The worst is when you are working on a motorcycle, changing a piston while the rest of the engine is still assembled. Then you have to wonder if the errant clip fell into the crankcase, just waiting there to create havoc.....

AV8TOR

RE: Removing Wrist Pin Clip
 

OK. The saga continues. It looks like getting the rings back is more difficult than removing them. I do have some spares and one of the original ones looks good. How do you compress the ring to get it started in to the wrist pin hole? Trying to put it in at an angle is not working. Dan.

RE: Removing Wrist Pin Clip
 

I use a scrawl or small tip screw driver and press one end of the circlip down into the grove while applying inward and downward pressure with my thump to the opposing side . Once you get the first end in start working your way around with the tool pressing the ring inward and down. You are slowly working your way around the ring flexing it into the grove. Be sure you start with the ring gap at the top (toward piston top), this way the ring will not end up with an end of the ring in the relieved area .

RE: Removing Wrist Pin Clip
 

Thanks CK. That’s what I wound up doing. What an ordeal. It’s going to be a disaster when I try to change the crankshaft bearings but not now. Here’s a website that has large assortment of internal metric retaining rings. The wrist pin diameter is 10mm. How about an educated guess as to which one is the correct one. I do have a tool that is capable of grabbing the built in holes and compressing the ring. Dan.
http://www.mcmaster.com/#retaining-rings/=npl2gt

RE: Removing Wrist Pin Clip
 

I would guess that for a 10mm bore you would probably need an 11 mm or slightly less than 11 mm ring .
Be sure of the thickness of the replacement ring is close to the width of the original. I would also be cautious of the rings you are looking at as they are flat cut and the groove you need to fit it in maybe a radius cut (square peg in a round hole theory at work here ) a flat cut ring will not fully seat in a radius cut groove and you don't want that kind of trouble. If it were mine I would use the correct retaining ring either find one for a 115 saw or get one from Bill Jenson

RE: Removing Wrist Pin Clip
 

Thanks. I'll send Bill an email. Dan.