Removing gudgeon pins from pistons

[Gc33]

Hi all. I'm at the stage where I need to remove pistons from conrod. I don't have a press avail however I'm considering purchasing a 1 tonne arbor press. Not expensive.
Im interested to know what technique any of you guys have have used successfully To remove the pins.
Cheers.

 

[DaveKamp]

Now, I'll preface by saying I haven't had need to move wrist pins from any GL pistons, but I've done MANY others... I THINK they're a light press fit... if so, pour a cup of alcohol in the piston, and light it. When the alcohol is all burned out, set it on it's side, push the pin out with a wood dowel. ;-) it SHOULDN'T take much thermal expansion to let those free.

 

[skiri251]

Yeah, are GL wrist pins any special?
I did my vintage bikes myself, Z50R, CL125A, IT175, BS200, A65T, but none of them needed a press.
You can make a pin extraction tool with a long bolt and pieces of metal.

 

[Gc33]

Thanks gents. Would using a heat gun get the same result? The reason I'm being cautious is that the pistons from my first engine I stripped are in good order so I'm using those in the second engine. 0.25 over and second engine is standard bore.
So I don't want do damage pistons or pins... I grew up with em being called gudgeons... But yes more correctly as listed in manuals as wrist pins.
The manual says to press them out... But if they are a light press then the heat should let em almost fall out..

 

[mcgovern61]

FYI - In nautical terms, it is Pintles and Gudgeons. Pintles and Gudgeons comprise the hinging mechanism on outboard-mounted Rudders. Pintles always incorporate a Pin, Gudgeons always have a hole for a Pin, either may be attached to the rudder or to the Transom. In standard configuration, Pintles are attached to the Rudder, and Gudgeons are attached to the Transom.

 

[Gc33]

mcgovern61 » Today- 11:01[/url]":2zkf9t67]
FYI - In nautical terms, it is Pintles and Gudgeons. Pintles and Gudgeons comprise the hinging mechanism on outboard-mounted Rudders. Pintles always incorporate a Pin, Gudgeons always have a hole for a Pin, either may be attached to the rudder or to the Transom. In standard configuration, Pintles are attached to the Rudder, and Gudgeons are attached to the Transom.

Thanks for the info, I have been enlightened today..

 

[DaveKamp]

Not the first time I've heard of a wrist pin referred to as a Gudgeon Pin... but then again, I'm pretty good with understanding foreign languages like Limey, Kiwi, and Aussie... I can even speak a little Canuck... after I've had too much Poutine... :smilie_happy:

If you can get enough heat on the aluminum with a heat gun, that'd probably let them loose from the piston, but I don't remember wether the 'wing holds the pin firm in the piston (and floats on the wrist) or vise-versa. I do know that if you've got an aluminum piston hanging on it's rod, a couple shot-glasses of isopropyl alcohol and a lighter, 5 minutes it'll be warm enough in both to basically fall out... just wear gloves, okay? :hi:

(btw... it's entirely appropriate and considered good practice in most places from West Sussex as far north as Derbyshire, to lift the bonnet of your neighbor's lorry to inspect for negative earth... but doing so in most of the US or Canada, she'll slap you hard enough to dislodge a tooth or three. :ahem:

 

[Gc33]

DaveKamp » 19 minutes ago[/url]":357relnm]
Not the first time I've heard of a wrist pin referred to as a Gudgeon Pin... but then again, I'm pretty good with understanding foreign languages like Limey, Kiwi, and Aussie... I can even speak a little Canuck... after I've had too much Poutine... :smilie_happy:

If you can get enough heat on the aluminum with a heat gun, that'd probably let them loose from the piston, but I don't remember wether the 'wing holds the pin firm in the piston (and floats on the wrist) or vise-versa. I do know that if you've got an aluminum piston hanging on it's rod, a couple shot-glasses of isopropyl alcohol and a lighter, 5 minutes it'll be warm enough in both to basically fall out... just wear gloves, okay? :hi:

(btw... it's entirely appropriate and considered good practice in most places from West Sussex as far north as Derbyshire, to lift the bonnet of your neighbor's lorry to inspect for negative earth... but doing so in most of the US or Canada, she'll slap you hard enough to dislodge a tooth or three. :ahem:

Hmmm... Tried all 3 of the above... Started with heat gun... Got a fair bit of heat on it... No movement..
Tried the alcohol method. Still no movement...
Tried gas... Still no movement. I'll have to wait a week now... Ive taken the engine casings into engineers with the pistons and rods... I can take them off after. I still need to get everything vapour blasted before I start painting etc.