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hiram
09-11-2020, 12:54 PM
The bushing in my Hart rifle rest is stuck. I don't know how or why. What you ae lookin at is the rest in a vice with a nut on the bottom and two pieces of wood holding the top of the bushing away from the vice jaw to give room to slide up. I tried penetrating and other oils, and a hammering a nut resting on the bottom of the bushing. I tried a thin screwdriver tip at the top between the bushing and the base. The rest was not used for a long time and this is what happened. No go. Ideas????????? I haven't tried heat.

Thanks

267563

John Boy
09-11-2020, 02:26 PM
Ideas?????????

https://www.hartcustomrifles.com/contact/

Winger Ed.
09-11-2020, 02:39 PM
You can trick it into thinking its being hit with a impact driver or air chisel.

Put it in the vise with a socket on one side, a bigger socket on the other so it has a place to go.
Tighten the vice down, then hit the jaw of the vice with a hammer to get a vibration going in it.

I've had good luck drifting out front end car suspension bushings and 'U' joint cups doing that.
Another option is taking it to a truck repair or shop that has a hydraulic bearing press.

Depending on what the bushing is made of, heat might make it expand more that the other part,
and make it even tighter..

hiram
09-11-2020, 04:46 PM
I believe it is cast iron -- really heavy.

Winger Ed.
09-11-2020, 04:55 PM
I believe it is cast iron -- really heavy.

A magnet will tell ya.

If the bushing is brass, I wouldn't heat it.
I'm pretty sure it expands or contracts more than iron with temperatures.
Maybe put the thing in the freezer awhile in the hopes the bushing will shrink, but I wouldn't heat it.

uscra112
09-11-2020, 05:01 PM
Alluvus in farm country know that the best penetrating oil by far is 50-50 acetone and ATF. Beats anything that comes in a can; even Kroil.

country gent
09-11-2020, 06:15 PM
Have you tried to turn / rotate it to break it free some. Im pretty sure the hart bases were a cast iron sand casting so heating isnt a real option. The best way would be to build a wood fire over it and let it heat evenly as the fire burns. this will create a slow even heating.

That bushing has the treads for the post in it if Im thinking right. It may be pressed and keyed in place. If so the best would be to find a press to push it out, are there any bolts or set screws holding it. Also clean the paint away and look for locking pins on it.

A make shift puller can be made with a short piece of pipe some threaded rod nuts and washers. A piece of pipe bigger and longer than the bushing threaded rod longer than the assembly washers and nuts. Assemble and start tightening the nuts down. This will provide a lot of even force in a straight line. 3/4" threaded rod fine thread if you can find it. heavy washers and nuts. This will provide many tons of force. This can be tightened down tight and left to sit and work on the part if needed.

uscra112
09-11-2020, 09:25 PM
That last setup is how we used to remove/install small-end conrod bushings in pre-1970 BMW connecting rods. In my rollcab I still have a similar setup, but I can't remember what it's for!* Anyway, use the largest diameter and finest thread you can for the through-bolt.

* Yes I do - it was for removing/installing Bultaco piston pins that are a press-fit in the piston when cold.

hiram
09-11-2020, 11:03 PM
This busing is not threaded. There is a 'T' handle screw that holds it in place if you want to adjust for more height.

uscra112
09-11-2020, 11:45 PM
So it will move if you can get enough force on it. Country Gent's puller scheme will do it.

EMC45
09-12-2020, 09:09 AM
I would heat it, then spray with penetrant of your choice (I say Kroil), let it sit until cool. Freeze it and carefully/gently try to press it out.

country gent
09-12-2020, 12:17 PM
To add to the puller I described think a stuck case remover. Its very similar. When you can get a straight even square pull or push it takes a lot less force to move it. Its probably rusted or corroded in place.

I would also recommend a brass washer against the bushing and between the washers nut to avoid damage. Use a stack of washers 3/8"-1/2" thick. the thread will give a lot of force and you need solid surfaces. As the bottom washers and nut pull into the casting a deep well socket will be required also. or more spacers.

hiram
09-12-2020, 10:26 PM
It's free. I had been putting penetrating oil on and banging away. Today I put the rest on the floor, upside down. I propped it off the floor with 3 small pieces of 2X4 to allow room for the bushing to move. On the bottom side, now facing up, I took a spark plug socket which fit very close in the recess now facing up. Took a lump hammer and in one shot it moved. The rest is history. It was rust. I cleaned it up with a wire wheel, polished a bit with emery on a cotton wheel. Lightly greased and better than new.

Thank you all for your help and suggestions.

country gent
09-12-2020, 11:02 PM
Glad to hear you got it up and going.