Did a quick search and nothing came up so here goes. What do you guys use to press the wrist pin out of connecting rod? I am going to put my new top end on my RD350 in a few weeks and wanted to know if you made items or just bought a puller online. Worried about damaging the connecting rod bearings if I get too aggressive, trying to alleviate any issues. Thanks
There are piston pin pullers, but you really don't need one. Lube it up, press in with your hands or lightly tap in.
https://www.economycycle.com/shop/tools-hardware/wrenches-pliers-related/piston-pin-puller-tool/
(https://www.economycycle.com/wp-content/uploads/2014/12/l204226.jpg)
i usually use mine to remove any risk of bending a rod, i have one of those it works great. :twocents:
Warm the piston
Cool the pin
A bit of oil
It slips right in
never had in issue getting one in, that's for getting it out.
Guess I mis-read that on the in/out, but generally IMO you don't really need one, maybe if it's seized and a real mess, but if things are that bad maybe time for full rebuild. You can use a block of wood to support the rod if you're that concerned. Never bent a rod tapping out a wrist pin and don't recall anyone that has or any posts/customers where that's happened. And sometimes they get hung up going in and need a light tap too. Maybe I should but it's just a tool I've never found necessary. :twocents:
Same here; I have the one John pictured, and it's almost pristine from non-use.
At the risk of hijacking this thread, my nephew is rebuilding an old Isuzu truck engine and was telling me that he's having difficulty pressing the wrist pins out of the rods. I've done my share of four-stroke top ends but haven't run into this. Is it typical of automotive engines?
some are pressed on the rod, some float. if it has clips it floats
I've experienced a piston that had a ridge worn in, 2 stroke, and the pin puller was a saving grace. do I always use it? no.
At the risk of outting myself as a barbarian I've just used a deep socket and C clamp on stuck pins.
Also on automotive pistons too Wade.
I think a C-clamp is a very civilized tool! Far more sophisticated than baby Thor
before i had that, i also did that. nothing wrong w it, but i mean i think i paid 15 bucks for mine. years ago. more tools: better life quality. :gentleman: :metal:
Quote from: m in sc on February 10, 2024, 05:45:54 PMi usually use mine to remove any risk of bending a rod, i have one of those it works great. :twocents:
I once bent a rod forcing a piston pin. Didn't realize it until I slid the cylinders on and there was too much friction on the side of the cylinder. That required a new rod and a crank rebuild. Buy a piston pin puller.
Normally, the problem is a tiny burr/ lip that has formed on the outside edge of the circlip groove. A quick cleanup of this burr with a pocket knife, small machinist's bearing scraper or other suitable tool is all that is required 99 percent of the time. After doing this you can push the wristpin out using very little force. Think about it; the wristpin bore in the piston is very unlikely to shrink with usage.....
if i can't just slide it out, i grab the puller. that tool exists for a reason. that's all i'm saying.
Quote from: 85RZwade on February 11, 2024, 12:34:42 PMSame here; I have the one John pictured, and it's almost pristine from non-use.
At the risk of hijacking this thread, my nephew is rebuilding an old Isuzu truck engine and was telling me that he's having difficulty pressing the wrist pins out of the rods. I've done my share of four-stroke top ends but haven't run into this. Is it typical of automotive engines?
Don't know for sure on Isuzu, but many car engines (American mostly) have press-fit pins no retaining clips. A hydraulic press is necessary.
Warren
Something has to locate/center the piston on the pin.
On these Yamahas, as most two strokes; the rod is located by thrust washers on the crank, and the rod "floats" on the pin.
On a four stroke you can locate the rod with a press fit pin and let the big end "float" on the crank.
No one noticed I wrote y'all a poem....
oddly, my old galaxies 390 (fe design from the 50s) had full floating pins when i rebuilt it. so its all over the place. My old 351W & other small blocks were press fit, as are the ford I-6's. :huh:
Quote from: m in sc on February 12, 2024, 08:29:45 AMif i can't just slide it out, i grab the puller. that tool exists for a reason. that's all i'm saying.
My reply was only meant for motorcycle 2-stroke engines. On my RD 350's cleaning off that tiny burr/ ridge makes a world of difference. If the wristpin is a push/ sliding fit in a new piston, the only difference when removing the pin from a used piston, are these tiny burrs at the edge of the circlip groove.
OTOH, I haven't removed any car/truck/tractor wrist pins in at least 30 years....
When I worked in a machine shop in the 70's most of the US built car engines had the press in pins. I always thought it was a way of ruling out circlip failure disasters and one less wear spot to cause more slop in the rod to piston fit that could cause noise.
ive never used that puller on a car engine, just fyi. no reason to since you have the rod off the crank to swap them out.
Im not sure many realize how easy it is to bend a 2-stroke rod to the side, even just a tiny bit.