The Stovebolt Site Forums The Shop Area Driveline Stubborn nut - 1956 Steering gear pitman arm

Attempting to disconnect everything from the cab of my 1956 Chevy 3100 so I can remove it and commence major cleaning. One major hurdle is attempting to remove the 1 1/2" nut that holds the pitman arm onto the gear box. I have sprayed it with Blaster solvent several times, used a breaker bar with a 1 1/2" socket, heated the nut with a propane torch, and used a small sledge hammer to try to loosen this nut. Have any of you run into this situation and what did you do to break it loose?

In the past when I ran into a stubborn bolt or nut (numerous times dismantling the truck bed on this 3100) I've used a power cutoff tool. I could do that on this but then there goes the gear box which is hooked to the steering column (which is a problem in itself).

Thanks for any advice you have.

Cordless impact wrench or air powered impact, they will knock it right off. Don't pull so hard you turn the steering box clear to the end, you could damage the internal gears or roller ball tracks. The nuts usually come off fairly easy, it's the arm that puts up a fight.

Try tightening the nut before loosening it. It was put on with probably 90 pounds torque and it may have galled the screw threads a bit. Occasionally tightening first will help it.

How hot did you get the nut? Did you try removing it while still hot? That would expand the nut away from the shaft a bit. If you cool it off it will actually shrink tighter than it was originally, so don't do that.

If it won`t come off with heat then I think I might cut down into one side of the nut
with a cutoff saw. I`d keep heating it up and spraying PB blaster or WD -40 while HOT. I`ve not noticed much of a difference
in the two lubricants used this way. Get a chisel and get a good bite on the edge of the square angle of the nut and give a good hit.

I’ve recently seen pouring ice water on it while hot. Seems to work.
My son tried it, I haven’t personally.

Try heating it up again and hit it with some Kroil, that stuff is amazing.

I haven't tried the impact wrench attack. That is the next thing I will try. I got the nut hot, but think if the impact wrench doesn't work I will heat it until it get RED hot, but not melting hot. I just got it really warm before. My brother-in-law farmer said to try the hot/cold trick, but holding off on it for now. Cutting a line in one side of the nut with a cutoff tool and then use a chisel to knock it loose is a good thought which I will try, as well. Thank you all for your great ideas. One or a couple is bound to work.

Well all of you were a great help. I got it off within 5 seconds with an air impact wrench. Now, as Joe H said, the Pitman Arm is being very stubborn. I'll be trying the Kroil along with heat and a good puller. Again, thanks guys, you're much appreciated!

I have a Pitman arm puller, but on my bus I still had to heat it up pretty hot with acetylene torch and then it slipped right off. If you don't heat it up, it will break the pulller... ask me how I know. I'm quite sure mine hadn't been removed since 1965, and despite anti-seize and more moderate heat, it didn't go quite as far back onto the shaft as the marks said it did from the factory. I tightened it so much I was afraid of ruining the nut, so I think it's past 90lbs/ft.

I agree with the Kroll comment. It’s the best penetrating oil I’ve found. If it sits overnight it can loosen most anything.

Just know, that arm is a taper fit, penetrating oil won't due much to a taper fit. Put the puller on and tighten the bolt till it about breaks, then hit the head of the puller bolt really hard with a hammer, bigger the better. Have the nut on the shaft so when it breaks free it doesn't hit you or something else when comes off.

If you go the heat route, there is a seal right at the housing that will likely get damaged, it's easy enough to change once the arm is off, and should be changed anyway, heat or not.

Us a puller made for idler arms, not a long arm gear puller.

I kind of did the same when removing mine years ago. Sprayed some PB Blaster, put a puller on and got it tight, then tapped on the arm like a tie rod end. Lots of taps and it finally popped off.