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TR2/3/3A Deep in the TR3 motor

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Moseso

Moseso

Jedi Knight
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Question of the day:
My little "1-ton" arbor press hasn't budged the wrist pin bushings the least little bit out of the con rods. What's it TAKE to get those devils out???
 
It sounds like moreso is talking about the bushings in the con rods, and not the wrist pin.

Is the mandrel you're using too large in diameter? The bore is a nominal 1.000" in diameter. Make sure the mandrel you're pushing with is slightly smaller then that.
 
I have 178,000 miles on my wrist pins from new. I changed the pistons 97,000 miles ago in 1990 and put the original wrist pins back in. This past spring, I put in new rings and the wrist pins were still like new - at least as far as I could tell by the smooth swing they gave me. They were well lubricated and seem to work fine. They must still be okay with the 4,000 miles I've done since then.

Why do you need to remove them ?
 
Warm up the connecting rods. That'll help you press them out.
Read his post closely guys. Art got it.
Wrist pin BUSHINGS in the connecting rods.
Not the pins themselves.
 
Banjo said:
Read his post closely guys. Art got it.
Click to expand...
And I totally missed it ! Sorry, guys.

Didn't try to measure what it took to push those puppies out, but I'd guess it was more than 1 ton.
 
Don Elliott said:
I'll ask again - even now that I got it that it's the bushings you want to press out - WHY DO YOU NEED TO TAKE THEM OUT ?
Click to expand...

They have more play than I want to see in things that are to be reused. I don't have the sweet measuring devices that could quantify my observations, but there should be no noticeable "wiggle" of the pin in the bushing -- and I can definitely feel play. They sure don't cost that much, though the tools to install 'em might. They need to be reamed after getting 'em in -- assuming I CAN get them in...

Martx -- My mandrel is an appropriate size. That's not the problem...
 
Moseso said:
I don't have the sweet measuring devices that could quantify my observations,
Click to expand...
So why not buy some ? You can pick up a 0-1" outside micrometer plus an set of telescoping bore gauges for less than $50 from Enco.
https://www.use-enco.com/CGI/INPDFF?PMKANO=130&PMPAGE=30
<div class="ubbcode-block"><div class="ubbcode-header">Quote:] but there should be no noticeable "wiggle" of the pin in the bushing -- and I can definitely feel play.[/QUOTE]I agree, shouldn't be able to feel the play. The book gives the clearance as only 2 tenths (.0002") @ 68F.

Shame you're so far away, I'd let you use my tools (including the press). You might ask your local machine shop what they would charge for the work, though. Shouldn't be too much.
 
Enco... Yeah! I'd forgotten about them. Thanks!

I do find it tough to spend $9.99 on what Starrett wants $149.00 for (the bore guage set). It's difficult to imagine how it could be the same thing. I've been stung on tool decoys before and generally prefer to buy the real thing -- especially when we want to measure .0002" and count on the results. I own a fine Mitutoyo 0-1" mic, and I've borrowed a couple of bigger ones from a friend to measure the crank and pistons. What I don't have is the bore guages. Maybe I'll give that cheap set a try...

Oboy! Another catalog to look through!
 
I have the ones from Enco. Certainly not the same quality as the ones from Starrett; but with care I feel they work well enough. There is some play between the housing and the expanding part, which is probably much less on the Starrett.

And of course, it does take some technique to get accurate measurements with them; you have to be certain the gage is across the diameter, the handle is parallel to the bore and so on. Usually it takes me a couple of tries to get a nice snug fit without being too tight.
 
Those aren't bore gauges, from either Starrett or Enco. They're just telescoping gauges. I certainly wouldn't trust them to accurately measure .0002".
For that, I use a bore gauge, equipped with a dial indicator that is graduated in .0001" increments.
The telescoping type are good for rough measurements.
Jeff
 
I've used telescoping gauges (expensive ones) to make highly accurate measurements. It's a little tricky, but once you get the hang of it, not bad.
I used to have a wood shop, right next door to a short-run/custom/prototype father-and-son machine shop. They were very generous with the loan of tools and advice when I was deep inside the motor of my BMW R69S motorcycle. I used their telescoping gauges and their mics to measure the pistons and jugs (BOTH of them!) and lots of other critical fit places in the heads (BOTH of them!) and the crank. Almost all of that stuff required accuracy in the ten-thousandths decimal place -- and their nice tools delivered it. I'm not certain, but I don't recall ever seeing them use dial bore gauges -- and they did LOTS of jobs ± .0001".
 
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