Circlip ideas and thoughts

[rupedoggy]

I have read several posts about circlip failure and thought I would try to help. I just took a 440 apart and the circlip had lodged in the piston. It was aftermarket. I could see where the original installer had tried a hundred times to get that clip in there. The scratches around the pin hole were numerous. The side that did not come out was barely hanging in there. It had lost all tension and was "oversqueezed".
With that in mind I got out all the old pistons and several clips to investigate:
1. Some of the clips are to big for the grove and stand proud to far. If over half of the clip is above the groove it can come out.
2. Some of the grooves are not cut completely around or are shallow in one place.
3. Some aftermarket wrist pins are a little to long and the original pin is to long also. Watch for this and for good square ends on the wrist pin.
4. If the Chinese clip has long tangs, cut them back a little.
5. Finally be sure the clip is all the way into the groove. It can seem like they are in when in fact they are just out a little or one side is out. Check with a flashlight.
That should be some advise for a rebuild without a re-rebuild because of bad clip placement.

 

[grizz55chev]

I have read several posts about circlip failure and thought I would try to help. I just took a 440 apart and the circlip had lodged in the piston. It was aftermarket. I could see where the original installer had tried a hundred times to get that clip in there. The scratches around the pin hole were numerous. The side that did not come out was barely hanging in there. It had lost all tension and was "oversqueezed".
With that in mind I got out all the old pistons and several clips to investigate:
1. Some of the clips are to big for the grove and stand proud to far. If over half of the clip is above the groove it can come out.
2. Some of the grooves are not cut completely around or are shallow in one place.
3. Some aftermarket wrist pins are a little to long and the original pin is to long also. Watch for this and for good square ends on the wrist pin.
4. If the Chinese clip has long tangs, cut them back a little.
5. Finally be sure the clip is all the way into the groove. It can seem like they are in when in fact they are just out a little or one side is out. Check with a flashlight.
That should be the some advise for a rebuild without a re-rebuild because of bad clip placement.

The accepted practice is to not use aftermarket circlips at all, go with OEM clips to be safe. The rest of the suggestions are solid.

 

[rupedoggy]

This I know, but the original clips don't always go into the slot deep enough because the wire size is different. Maybe that's why you have lost a piston or maybe you didn't. I have never had a clip come out. You can use the original wrist pin also but grind it down to the same length as the Chinese. Mike

 

[67L36Driver]

Good points there. [emoji106]

One can remove retainer ring tangs completely provided the piston has a removal notch. Or, jut remove ‘em anyway. Risk is a more difficult ‘do over’.

Sometimes the OEM and aftermarket retainer are a different wire diameter. Therefore be very careful when using OEM in an aftermarket piston.

Piston pins are often chamfered on the end (OEM), where aftermarket are not always.

As a rule I don’t mix OEM piston/wrist pin/retainer with aftermarket as they are not always compatible.

Shorten the overlong retainer tangs.

 

[Deleted member 117362]

Buy more than one, mine seem to grow wings every now and then.

 

[grizz55chev]

This I know, but the original clips don't always go into the slot deep enough because the wire size is different. Maybe that's why you have lost a piston or maybe you didn't. I have never had a clip come out. You can use the original wrist pin also but grind it down to the same length as the Chinese. Mike

I believe there’s more to it than just wire gauge, it also has to do with the quality of the wire used. AM clips tend to not retain their shape as well as the OEM clips.

 

[67L36Driver]

Very difficult to see here but OEM pins have less (or no) chamfer.

And bore is smaller, no taper.

 

[rupedoggy]

OEM lighter

 

[pioneerguy600]

One thing I always do is rotate the circlip in its groove until the open is facing the wrist pin, if the circlip will move,slide and rotate it is likely to be seated completely in its groove. I will add that if a piston does not have a removal indent in it already it is very easy to make one with a Dremel and bit, some AM pistons do not have the indent or removal slot to help pick the end of the clip out for removal.

 

[dmb2613]

If you use the china clips they will fail , they have little to no spring tension. The OEM clips are smaller in diameter but I have never had one to come out. Take it for what its worth!

 

[67L36Driver]

Yup, an ice pick is your friend. [emoji106]

Remember ice picks from way back when the vending machine dispensed block ice? Twenty five cents got you a ten pound block.

It’s a geezer thing.

 

[pioneerguy600]

Yup, an ice pick is your friend. [emoji106]

Remember ice picks from way back when the vending machine dispensed block ice? Twenty five cents got you a ten pound block.

It’s a geezer thing.

Vending machine? Horse and wagon delivery and ice box instead of a fridge, cut the ice cakes right off the fresh water lakes all around me.

 

[Huskybill]

Time to look for some inside diameter spring “c” clips from McMaster.com to replace the garbage there selling us.?
Click on internal ,,,,,,,,,
https://www.mcmaster.com/retaining-rings

https://www.mcmaster.com/retaining-rings

Unless we purchase the correct diameter spring wire and make them ourselves?

One piston kit came with two sets of c clips I opened up today.

 

[Huskybill]

Yup, an ice pick is your friend. [emoji106]

Remember ice picks from way back when the vending machine dispensed block ice? Twenty five cents got you a ten pound block.

It’s a geezer thing.

I have ice picks somewhere with ice tongs.

 

[pioneerguy600]

Time to look for some inside diameter spring “c” clips from McMaster.com to replace the garbage there selling us.?
Click on internal ,,,,,,,,,
https://www.mcmaster.com/retaining-rings

https://www.mcmaster.com/retaining-rings

Unless we purchase the correct diameter spring wire and make them ourselves?

One piston kit came with two sets of c clips I opened up today.

Those internal and external circlips in your links are not designed for high RPM use, there is too much weight in them for that kind of application so I think they would be more susceptible for being dislodged.

 

[Huskybill]

The only other choice is to purchase the spring wire and fab our own. One side of those internal clips is rounded. If we file or stone the opposite side rounded it might work.

 

[hotshot]

Poulan (& Lawn Boy mowers) both did indeed use those internal snap rings for years in the 306 & 245 series pistons. But those reed valves saws topped out at 7000 RPM or so.

Never seen one come out & great to remove/install with snap ring pliers. The tool that cuts the groove for the clip has a square ends, not round.

There’s an old thread about heat treating, quenching & annealing the soft import C clips to increase spring back, but I couldn't find it though...

 

[cuinrearview]

The only other choice is to purchase the spring wire and fab our own. One side of those internal clips is rounded. If we file or stone the opposite side rounded it might work.

It's not the only choice. One could just purchase a set from the dealer

 

[PogoInTheWoods]

My experience leans toward most circlip 'failures' being related to the method (or lack thereof) applied to installation..., as perhaps sort of implied in Mike's introduction to the subject.

The other main reason is incompatible fitment of the clip in the groove, either from lousy manufacturing tolerances in the first place or simple negligence related to inspecting what type of fit you actually have once the clip is installed. Most guys are just happy to get the damned thing in there without shoving a pic or mini-screwdriver through their finger and call it done..., then blame the clip if it becomes dislodged and trashes everything. "Yep. Shoulda used OEM."

The above said, I see clipping tangs or ears as a Catch-22. Some believe they're points of failure. I don't necessarily agree and would argue that removing them actually increases the chance for a failure due to additional (and probably uneven) stress being put on the clip during installation vs. what would otherwise be an easy snap and go with a pair o' needle nose pliers. That's an over generalization, of course, but the less stress and uneven distortion a clip sees during installation, the better -- OEM or otherwise. Lots of OEM clips did, or still do, have ears or tangs.

As mentioned, if the clip is seated deep enough into a uniform groove and hasn't had its general strength adversely affected by a ham handed installation, it should have no reason to move laterally unless being hammered by the wrist pin which is physically highly unlikely unless the needle cage has failed. Hell, McCullochs don't even use circlips.

Be interesting for someone with way too much time on their hands to do some comparative strength and dimensional testing among a batch of OEM and AM clips to see where the chips actually fall.

 

[grizz55chev]

The only other choice is to purchase the spring wire and fab our own. One side of those internal clips is rounded. If we file or stone the opposite side rounded it might work.

OEM clips are already designed for their job, and they’re cheap, no need for modifications. We’re talking about a part that is simple, yet extremely important.