How to pull a Gib ?

[vdubnut62]

Some body might be interested in the 50/50 mix of acetone and ATF for penetrating oil. You utterpower guys should be familiar with it



Machinist's Workshop magazine actually tested penetrants for break out torque on rusted nuts.  Significant results!  They are below, as forwarded by an ex-student and professional machinist, Bud Baker.




April 2007 "Machinist's Workshop" magazine comparison test.

They arranged a subjective test of all the popular penetrants with
the control being the torque required to remove the nut from a
"scientifically rusted" environment.



Penetrating oil ..... Average load*



None ..................... 516 pounds
WD-40 .................. 238 pounds
PB Blaster ............. 214 pounds
Liquid Wrench ....... 127 pounds
Kano Kroil ............. 106 pounds
ATF-Acetone mix.......53 pounds



The ATF-Acetone mix was a "home brew" mix of 50 - 50 automatic transmission
fluid and acetone.  Note the "home brew" was better than any commercial product in this one
particular test. Our local machinist group mixed up a batch and we all now
use it with equally good results.





Troy Oscar

Sr. Product Engineer

ROUSH






Good luck! Ron

[Crumpite]

Very, very interesting results !

Thanks for posting this info - it has a couple of surprising results, at least for me.

I've used ATF for many things in the shop and I can see how adding acetone to the mix would help it even more.

Looks like I won't be spending my cash on Kroil anymore !
Daryl

[Geno]

This looks like a good method...

Where can we get metal wedges like the ones you show in your example?
Are they a standard tool which is usually easy to find?

Thanks,
veggie

http://www.hitnmiss.com/24.html#keypull

As earlier stated, slow and easy is the way. I had to deal with a broken head a few years ago and I thought I was taking it slow and easy. Now I have one of Mike Montieth's gorilla pullers.

Thanks, Geno

[AdeV]

Where can we get metal wedges like the ones you show in your example?
Are they a standard tool which is usually easy to find?

Although not exactly like WGB's taper, you might be able to use a drill drift key (aka morse taper key, taper drift key, or any number of variations); these are tuppence ha'penny¹ and available pretty much anywhere, e.g. eBay, McMaster, RDG Tools, etc.





¹ About £2.20 from RDG Tools, or $10 from McMaster (seems steep...)

[mbryner]

Hey, why make it that complicated?   I just used a wood splitting wedge that I had lying around.   Worked great!   

(and i'm a full member now, woohoo.)

[veggie]

Just to complete the discussion.....
What's the proper way to re-install a gib key?

How hard do you hit the thing?
How does one know when it's properly seated?

veggie

[vdubnut62]

Magic Jack did a fairly involved step by step tutorial on gib key fitting, but for the life of me I can't find the article!
You might PM him for a link?
Sorry I can't help!
Ron.

[BruceM]

Magic Jack's explaination is the best, but here's one that's OK, from the LES:
    Re: Another Gib Key Saga
« Reply #4 on: May 14, 2006, 12:16:21 AM »
   Reply with quote
"Properly seated" is the key (pun?)

I just replaced my gib keys which I had really mauled getting them out the first time.  I could see they were only contacting the flywheel keyway at a single point.  Spent an hour or so with a sharp mill file and a Sharpie marker test-fitting the keys into the flywheel until the point of contact had broadened to cover most of the surface.

You can paint the tapered side of the gib key with the sharpie, then tap it in gently to the keyway and remove it and note where the black ink has been scraped off.  That is a high spot.  File the high spots down, reapply ink and keep test-fitting until the high spots broaden and take up most of the surface of the key.  Then you're ready to set the key.

The broach that was used to cut the keyways in my flywheels was evidently dull and/or had been resharpened.  Keyway was appx 0.005" deeper in the middle of the keyways than it was near the edges.  Took a pass using another file to the flywhel keyways and removed a bump that was causing me grief, too.

A few light taps later and the key weren't going nowhere.

I think the Indians must set those keys with a sledge hammer to ensure they don't come out, hence the sad tales of broken gib keys and mangled crankshafts.

There is always a little clearance between the sides of the gib key and the keyways.  One thing that might help to loosen a key would be to place a piece of appx 1/4" steel plate against the exposed side of the key protruding from the keyway in the crankshaft and whap it hard with a ball peen hammer a few times, then squirt penetrating oil in the joint.  Then whap the other side of the key and oil it, too.  Once you get some movement, the oil should be able to penetrate and do its job.

Halfnuts

[veggie]

Thanks BruceM,

Very useful information.

vaggie

[BruceM]

Here's Magic Jack's description from LEF:

Seating flywheels and gib keys---


Use the jaws of the vice as guides to draw file the bottom of the key .005" at a time.  Break all the corners on the key while fitting.  The Indians used dull broaches for the internal keyways.

Stop when you have even contact on the top and bottom of the key with an inch of head sticking out when snugged in pretty good but still pullable by levering it out with the top jaw of a pipe wrench.

Clean both the hub and the shaft with brake clean and then wipe with a dry rag and lime or chalk powder.  Scrub the shaft and the bore with lime.  Wipe off excess dust but DON'T touch it with bare fingers!  Degrease and wipe the key with lime, too.

Slide the flywheel into position and slide the gib key in until it stops.  There should be about an inch of head showing.   Use a large punch laid in the key way so your  hammer hit is straight on.  I use a one inch brass bar and a 4 pound double jack hammer but just for the weight of it, not the power.   You're driving a WEDGE in this wheel. Don't over do it.

The key should SEAT so solidly the wheel will suddenly 'ring'.  I can't tell you how hard to hit it, but the same lick with the same hammer would drive a staple half way in a cedar fence post.    Grin

By the way-- No finger prints, total non-acid and no moisture enviornment, between the wheel and the shaft means it'll still be rust-free a hundred years from now.

[veggie]

BruceM,

Thanks for taking the time to dig that up.
Everyone can benefit from that information.

veggie