Power steering diagnosis help

[MoFormula]

So, stopped off at the parts store for a new headlight. Got back in the truck to leave and steering was really stiff. Drove the truck home. Fluid was low but still showing on the dipstick. No whining or growling from the PS pump. Just really odd. Other relevant facts...1972 GMC 1/2 ton 2wd LB, steering gearbox replaced a year ago, lowered 5" in the front with most suspension parts replaced. Have been driving it for a year with the current setup. Any advice on where to start diagnosing this?

[mister.freeze]

I've been driving my 4x4 almost 20 years and same thing happened to me this weekend. Sprung a leak on top of the gearbox too. Anyone?

[RodnRudy]

I'm dealing with same problem. When I start driving the steering is fine but after it is warmed up the steering is real tight when I try to park. As long as I'm rolling it is fine. Fluid's full and it has a rebuilt Cardone pump from Rock Auto. 4500 miles on the pump. Mine is a 68 2WD

[mister.freeze]

I've got a gearbox ordered under my lifetime warranty. My hydraboost works just fine, so I don't think it's the pump.

[mister.freeze]

Now the gearbix is 'backordered' and O'reilly doesn't know how to hnor the warranty. Gonna try a box off a newer truck to see if it fits... how long did GM use the 72 stock box?

[PanelDeland]

The later gearboxes are 3 1/2 turns "lock to Lock". The originals are 4 1/2 turns LTL. Later box is a variable not that it makes any difference t the discussion. I find the original gearbox to be too soft "Squishy" if you will, for my taste. The later box has more feedback feel to it in my opinion and I used one in my 68. I think 73 was the first year for the newer box.

[harpo231]

Deland I find the last quote on page offensive !

[mister.freeze]

Gearbox in and hydraboost replaced. Stiffness is gone, but not as loose as I'm used to. The pump whines like it's low on fluid some now. I'm guessing air that has yet to work it's way out. Maybe back off the top bolt a quarter turn or so? Also, best method to clock the steering wheel?

Note: my 18-year-old receipt with part number translated to a gearbox off an '86 Silverado. Smaller input shaft required a $60 coupler (rag joint). The return fluid fitting had to be changed too. Otherwise, bolted up as it should.