D-179 wrist pin bushing

[Noblefarm43]

Hello

I'm working on a D-179 in a 464 and I have a question about replacing the wrist pin bushings. In previous engines I've done the bushings were so worn there was no question about replacing them. However this motor appears to have had at least a partial motor job done before I bought the tractor several years ago.

I don't have a micrometer just a caliper and telescoping bore gauge. Near as I can tell number 1 and 3 pistons are within the .0005 to .001 listed clearance between pin and bushing but number 2 is .002 in clearance. None of the bushings appear scratched up but all 3 are a different color on the bottom half than top half.
I have the new bushings and instinct tells me to replace them as long as I've got them out just wondering if its worth the hour trip to the nearest machine shop.
Thanks for any advice.

 

[rustred]

i would replace them as they show wear already. its kind of a fine line between too tight and too loose. these must be full floating pins? dont have an exact measurement. but they should just slide in with both at room temp. have to be honed to fit. i would not say yours are excessivly worn but appear to be on the way. good machinists know the spec.

 

[Janicholson]

.002 will knock. it will make noticeable noise. The others are marginal. I like .0005 to .0008 clearance. Appropriate rod conditioning is cheap satisfaction. Jim

 

[teddy52food]

1 to 3 ten thousands is what we fitted them to when I worked in the machine shop.