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View Full Version : Wrist Pin Circlip install tricks?



Brad Smith
5th April 2009, 11:41 PM
How embarassing. I used to see photos for Gudgeon Pin Circlip installation tools (A tube inside of a tube w/ fingers if I remember right) in books but never paid attention to them as the domestic stuff I am used to was always either spirolocs or the "C-clips" or "Circlips" had either a 90 degree bend on the end that you could grab w/ needlenose pliers to twist them out, or the usual clips w/ holes for snap ring pliers for floating pins.
I can push the 1st circlip straight down into the pinbore and then pivot it so that it will expand into the groove, fairly straight forward w/ room to work as the wrist pin isn't installed from the other side of the piston yet. However the issue is trying to decrease the diameter of the 2nd circlip so that it will go into the pin bore and expand into its groove. Can anyone advise what the trick is without damaging the side side of the piston and/or poking a hole in one of your mitts when trying to compress the round wire heat treated circlip? It would be nice if I could simply use regular circlips w/ snap ring plier eyes but those of course are square cut and the groove for these is of course round. There is no substitute for experience. I didn't find a thread for this using the typical key words but there has been mention about screwdrivers and being careful in other threads but didn't go into detail.
Grinding the end flat on one of the old wristpins "gudgeon pins" didn't help as a driver even though they put a taper at the leading edge of the pin bore for this purpose obviously...

Will
6th April 2009, 08:14 AM
Hi Brad:
I saw that needlessly complex FIAT tool also and I didn't have one either so I made my own much simpler version:

Just take a block and bore it through at wrist pin diameter and bore a concave on one end at 22mm radius. Use a wrist pin to align it with the hole in the piston and clamp it in place. Now you can use it as an extension tube to do the same fitting technique you used on the first side.

If you grind an old wrist pin to a 5 degree or so angle on one end and add a "T" handle to it, you'll have a very handy tool for seating the clips via turning and pushing.