Removing wrist pins from pistons 76 RUDE

[jim_in_day]

Help, the service manual has me confused (thats pretty easy to do). The pistons are marked with an L for the loose end of the piston. Ok, I can understand that. However, it says, and I quote "When wrist pin is to be removed, "L" side of piston must be up and arbor pressing tool must be applied to loose side. Always press from loose side to tight side being careful not to distort piston" THAT SEEMS BACKWARDS (sorry if I shouted) But it seems to me that pressing the wrist pin thru the tight side would be more likely to cause distortion than pressing the tight side towards the loose side to get it loose. Then to put wrist pin back in you would press from the loose side to the tight side. What is wrong with my thinking?

 

[F_R]

Re: Removing wrist pins from pistons 76 RUDE

The book is correct and your thinking is flawed. The tight side is down, because if it were up, it would "stick" to that side of the piston and distort the piston as the pin moves down, pulling the piston side with it. It is correct, you press it all the way through and out the tight side. It helps to warm the piston up a bit. But don't get it too hot, it might gall the pin bore.

And yes to reinstall you slide it through the loose side and then press it home into the tight side, the tight side being supported.

 

[jim_in_day]

Re: Removing wrist pins from pistons 76 RUDE

ok, thanks, I am being very careful to do this entire rebuild by the book, and want to make sure before I do anything that I understand it. We have the correct piston cradle to do the job, so support is not a problem, just my understanding of why (which you did a great job of clarifying) the wrist pin removal instructions were what they were.

 

[R.Johnson]

Re: Removing wrist pins from pistons 76 RUDE

Put the piston in a coffee can of hot oil at 200-250 degree's. That pin will come right out of there. Don't try this in the wife's kitchen.

 

[jim_in_day]

Re: Removing wrist pins from pistons 76 RUDE


WOW, thanks for the hint, I will try that, Maybe a little difficult to explain to the wife as to the oily smoke and stench in the ktichen, so i am in complete agreement with you on that.

 

[Dhadley]

Re: Removing wrist pins from pistons 76 RUDE

Are you sure you're not going to bore the cylinders?

 

[jim_in_day]

Re: Removing wrist pins from pistons 76 RUDE

DHADLEY thanks for peeking in. I definately have to bore at least 1 cyl. and replace that piston, the other 2 remain to be seen, have to wait until precise measurements are made, if required (out of tolerance) then they get bored. However, it seems to me that I can reuse the connecting rods since they are not damaged. I will however be replacing the needle bearings in the wrist pin end regardless of whether or not I have to bore the bottom 2 cyls. And I may just replace the 2 bottom pistons with new standard pistons if I don't have to bore the holes (just to be on the safe side). I know that I don't want to have to do this again because I didn't do something I should have done the first time, even though my wallet is going to complain in the short run.

 

[wilde1j]

Re: Removing wrist pins from pistons 76 RUDE

Pins go back in easily if put in a freezer for 30 minutes, then quickly pressed in place before they warm up.

 

[R.Johnson]

Re: Removing wrist pins from pistons 76 RUDE

Pin's are best put in at room temperature, or slightly warmed. You do not want to introduce a thermal shock to that expanded aluminum bore. Freezing for a press fit is another tale that just will not go away. I mean here that the piston is warmed before installing the pin..

 

[klicknative]

Re: Removing wrist pins from pistons 76 RUDE

I've never had a problem putting wrist pins in the frezzer to install them. Just don't heat the piston so you can't handle it with bare hands.