Vintage Sears Garden Tractors
Here's how I did it....
The stubborn steering wheel
The steering wheel can be a major pain to take off. You'll need to do this if you are going to restore your tractor. You will have trouble getting the dash off if you don't remove the wheel. The best advice I can give to someone performing this sometimes harrowing job is---be patient. If you try to force the steering wheel off with a puller, the most likely result will be a broken wheel. Lots of penetrating oil over at least a week's time, along with vibration set up by the use of a hammer, will do the job of loosening what seems like a welded on wheel.
After removing the spring clip, which holds the wheel on, you will notice that there is a key that keeps the wheel from spinning on the shaft. See if you can use a small punch to push the key down in the keyway a little. If it moves down, the space will create a small reservoir for your penetrating oil. Rotate the wheel so that the keyway faces the 12 o'clock position. Put penetrating oil in the keyway and around the shaft. Use a ball peen hammer to strike the center of the steering shaft lightly so as to create vibration between the parts. Be careful not to mushroom the end of the shaft with misdirected hammer blows; it will make it even harder to get it off. Try to use the oil/hammer routine once a day for at least a week. The wheel in the picture started coming off by itself during this treatment.
Using a gear puller, put some upward pressure on the wheel. Strike the end of the puller with a hammer to see if the wheel starts to come off. If it moves, the puller should become loose, requiring you to tighten the bolt more. If it doesn't move, CAREFULLY put a little more pressure on by tightening the puller some more. Strike it again. If it still does not move, go back to the oil/hammer routine again for another week. If it does move, keep tightening/striking the puller until you remove the wheel. Make sure the point of the puller stays centered on the shaft. Be careful that you don't overtighten the puller and damage the steering wheel!  Steering wheels from other brands will fit, but why not keep the original? The plastic wheel is EASY to damage with the puller.
IT'S OFF!  The penetrating oil had gone all the way down through the minute space between the steering wheel and the shaft over a week's time. This particular tractor had apparently spent most of its life outside and was extremely rusty. Check out the rim on the Amp meter in the picture above to get an idea of the rust. It's supposed to be chrome. There was no center cap on the wheel to keep it dry. Once the wheel is off, take some emory cloth and clean up the shaft and inside of the wheel. It will make re-installation a lot easier. BTW, the shaft is 3/4" on this '68, SS12.
When you go to put the wheel back on, a 15/16" socket works well for a driver. Do yourself a favor and put a piece of wood over the end of the socket before you wail it with a hammer and distort the ratchet end of the socket. (Been there and done that, the square hole won't be 1/2" any more.) Whatever you use for a driving device, make sure it contacts the metal bushing in the center of the wheel. Don't forget to put the key back in the keyway. You might have to support the other end of the shaft; it may bottom out before the wheel is all the way on.  
Click on photo to enlarge
Click on photo to enlarge
Click on photo to enlarge
Click on photo to enlarge
All material © 2000 Spence Ware