OT - How hot to expand enough...?

Page 1 of 2  
Howdy,
I threw the chain on my 6' tractor mounted snow blower (because the master link cracked...)
In order to replace and adjust the chain, I have to disassemble part of the blower.
There is a universal joint that is keyed, and its yoke slips onto the drive shaft. Or, more accurately, it slipped on when everything was new, and clean.
Getting it off has proven to be pretty tough. Using various wedging techniques, I managed to get it off for all but about 1/2" of its length, but I have not had any luck moving it further than that.
And so, this question:
I know that by heating the yoke, I should be able to get some expansion, and that should make removing it a bit easier, but I have no idea how hot I want it to be to have benefit, but without damaging the thing.
Also, whatever (approximate) temperature I was to shoot for, how would I know when I was there?
I am clueless, and would appreciate any help on this hassle.
My torch, and I await...
Many thanks,
--
Kenneth

If you email... Please remove the "SPAMLESS."
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Kenneth wrote: ...

Are you sure you don't have any side torque?
...

...
When it starts showing red, move the torch on around.
Do it as quickly as possible to get as little heat transfer to the shaft as possible. I usually fill it full of WD4O or another (relatively) non-volatile lubricant first. Seems to help some as it sizzles but won't start a big flame.
Have the pulling gear all set before start, of course, so doesn't just cool back down. Good would be if have an extra hand who can apply the tension or can arrange where you can do it together--then when it begins to move you don't need to keep on heating...
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:
Hi again,
Please see my comments inline...

I can't be positive, but I do not think so. I have moved it both ways several times and each time it hangs at (roughly) the same point. I doubt that I would have it twisted at the same point each time.

I am astounded that I would want it that hot, but am happy to give it a shot. Right now, the thing is one very heavy paperweight.

Thanks for the speedy response, and the great suggestions,
--
Kenneth

If you email... Please remove the "SPAMLESS."
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
dpb wrote:

WD-40 is NOT a lubricant.
WD-40 is NOT anywheres near "non volatile" basically kerosene, it burns quite well.
s
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Steve Barker wrote:

It flashes w/ the torch and works quite nicely for the purpose...
I never said anything other than it works as a wetting agent and tends to (it appears from many trials) to help in getting dirt out of ag splines like the aforementioned PTO shaft subject thread. It's not for any long term lubrication for the application.
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On 2/20/2009 5:06 PM dpb spake thus:

IANAM*, but I'm pretty sure that red-hot is too hot. I think you'd basically be annealing a hardened steel part, which is probably not what a guy would want to do.
* I am not a metallurgist.
--
Personally, I like Vista, but I probably won\'t use it. I like it
because it generates considerable business for me in consulting and
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
David Nebenzahl wrote:

I told him when it starts red, move...
If he's got some tension on it, it'll move before then.
The casting won't be particularly hardened; it'll be all right as long as he doesn't go overboard.
I've done many, most on combine header shafts that "grow on".
--
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 20 Feb 2009 18:11:59 -0800, David Nebenzahl

I anneal before no man.
I think you're right.

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Why won't the last 1/2 inch come off? Is it getting tighter, or are you just out of removal leverage.
Metal can change when heated especially heat treated parts.
Do not make the yoke glow at all. Your best bet is to have your pulling device ready and heat the part as fast as you can so that the shaft stays cooler. No need to go above 600 degrees.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 20 Feb 2009 21:17:26 -0500, snipped-for-privacy@mucks.net wrote:

Hi again,
It appears that the last part of the shaft is rusted, and with that, yes, as I move the yoke off, it does appear to be getting "tighter." It is not a leverage issue.
You suggest not going higher than 600 degrees, but...
How might I know when I am somewhere near that temperature?
Thanks for any further thoughts,
--
Kenneth

If you email... Please remove the "SPAMLESS."
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 20 Feb 2009 21:31:30 -0500, Kenneth

When doing this one usually uses a rose-bud torch so that the part can be heated quickly. Just keep the part from getting hot enough to glow and you should be ok.
If it won't move use bees wax and let it flow into the tight spot through capillary action. Return the yoke to its original position and use more bees wax. Try again.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 20 Feb 2009 21:53:02 -0500, snipped-for-privacy@mucks.net wrote:

Hmmm, bees wax?
I've not heard of that use before...
I assume that you are suggesting that I apply it when the parts are hot, so that it can flow. Interesting.
Thanks,
--
Kenneth

If you email... Please remove the "SPAMLESS."
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 20 Feb 2009 18:32:45 -0800 (PST), Pat

Hi again,
It would be impossible to describe the problem verbally, but there is no way to use a puller. Earlier today, when I was away from the machine, I thought that it might work. I headed back to my shop, grabbed a puller, and took it to the blower. It was immediately clear that it could not work. I just can't get any pressure to the shaft because the yoke of the universal is in the way.
Thanks for any further thoughts,
--
Kenneth

If you email... Please remove the "SPAMLESS."
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Have you tried hammering the u-joint back on as far as it will go and sanding off the rust n the outer section that is binding? That and some 90 weight lube oil might let it slide off. Gear oils are exceptionally slippery which is why they are used in auto final drives and such. Use a brass drift on the u-joint to avoid damaging it. HTH
Joe
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 20 Feb 2009 19:57:41 -0800 (PST), Joe

Hi Joe,
That is another good idea, and I would take that approach.
But when I hammer the yoke back on (as I have done a few times) virtually none of the shaft sticks out in front, so there is nothing available to sand.
I had tried it for another reason:
I knew that nothing would be available to sand, but I thought that simply sliding the yoke back on would abrade the surface of the shaft helping the situation.
Each time I did that, things did get a little better in that I was able to move the yoke off further.
I guess that I will have to try that a few more times, but it has been very slow work.
Thanks,
--
Kenneth

If you email... Please remove the "SPAMLESS."
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Kenneth wrote:

Any way you can rig something onto the business end of a slide hammer to bop it off with?
You didn't describe the universal joint in detail, but if it's still all assembled I'd be leary about using heat because of possible damage to the bearings or other parts of the U-joint.
Jeff
--
Jeffry Wisnia
(W1BSV + Brass Rat \'57 EE)
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Kenneth wrote:

I saw a History Channel show on locomotives. In the show, they demonstrated how they changed the tires on railroad cars (yes, they do have tires). They heated the sucker up until the tire expanded and it popped right off. Then they took a new (and hot) tire, pounded it on the wheel, and let the thing cool.
So, I suppose heating the object - whether a yoke or a railroad rim - is sufficient.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

This is my favorite trick, heat it up with a torch not too hot then apply candle wax to the joint. Hot candle wax is a very good penetrating lubricant. Works for rusty nuts and bolts and problems like the OP has.
Jimmie
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Fri, 20 Feb 2009 19:31:50 -0800 (PST), JIMMIE

Hi again,
Any hints about what "not too hot" might mean? <g>
Thanks,
--
Kenneth

If you email... Please remove the "SPAMLESS."
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

Not hot enough to effect the metal temper. I just got through using this technique a few minutes ago on some rusty U bolts. The guy I was working with had been a mechanic in the Navy for 8 years and he was impressed by how well it worked.
Jimmie
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.