how to diagnose bad steering gear box

[howlinwolf]

1978 chevrolet k10. there is a lot of play in the wheel without the wheels turning at all, and when the truck is running (the power steering pump is r unning as well) the shaft that comes out of the bottom of the box moves in and out approx 1/8 or more.  also when it moves in and out it pops, and the truck is kinda drifty? it doesnt seem like a death wobble, just sorta sighs as you turn the wheel

[bd]

Look closely at the steering gear-to-frame mounting for any cracks radiating from the frame bolt holes.  It's a given that the frame will eventually break there, especially on a 4x4.  While you're there look at the crossmember mounting as well and for any telltale rust. 

At the very least, the steering gear needs to be adjusted (assuming no internal damage or abnormal wear).  When a gear is properly adjusted, the Pitman shaft will turn in concert with the input shaft, with no delay or play between the two.  The Pitman shaft should have zero-to-nominal end-play.  Once you get the gear properly adjusted, inspect the tie-rod/draglink ends, Pitman arm end, and idler if it has one - all the way out to the wheels.

[howlinwolf]

how do you adjust the gear

[bake74]

1978 chevrolet k10. there is a lot of play in the wheel without the wheels turning at all, and when the truck is running (the power steering pump is r unning as well) the shaft that comes out of the bottom of the box moves in and out approx 1/8 or more.  also when it moves in and out it pops, and the truck is kinda drifty? it doesnt seem like a death wobble, just sorta sighs as you turn the wheel

     This sounds like the steering box needs rebuilt to me.  The internals have more than likely worn out.

[bd]

The attached PDF file contains the P/S gear teardown/assembly/adjustment procedure.  With the wheels pointing straight ahead, I would try adjusting the Pitman shaft end-play (sector/worm lash), first.  If that doesn't help, Bake74 has nailed it with a rebuild.  Let us know.

[howlinwolf]

the adjustment nut and shaft were seized. actually split where the allen key fit, so i opted for a reman from advance. huge improvement. there is still end play, but i guess its normal.

[slammed79]

Your tierods and bushings could be worn out too, that would explain any residual slop.

[bake74]

Your tierods and bushings could be worn out too, that would explain any residual slop.

      Do what is referred to a dry check on your front suspension components, while truck if off, check all steering components  for movement while someone is moving steering wheel back and forth.

[howlinwolf]

the bushings are worn out, the tie rods are good as well.  i replaced the steering box, and that fixed the problem. two weeks later, while helping move my inlaws, the spool valve in the new box goes bad.
  Got it replaced under warrenty and we are golden again. thanks guys! now on to bushings and a/c