by Jim Thompson
Speaking from experience....
...as to the quality (or the lack thereof) of Rebuilt Boxes coming from outside the USA. Ones to avoid are those that have been painted Grey as they are actually done in Mexico (I know the person that is directly bringing them into California and I won't touch 'em). I pulled apart one of these about 18 months back. Do you know they don't even machine the Steering Output Shaft? Or the Steering Peg or Worm Input Shaft? They (shudder) glass bead blast the things. Sure makes it wonderful preventing leaks even with a new seal. They don't even re-bush the housings which makes for a lot of side play slop in the shafts.
Even with all of their problems, the boxes rebuilt and sold by Bus Boys are a far better unit (as rebuilds go) as the shafts and pegs are re-machined to bring 'em back to specs and new silicon-bronze bushings are installed in the housings. To be sure, during the 4.5 years I was there, they did have a defective unit here and there, but overall they were pretty good units.
A note on the Pittman Arm - TRW rebuilt boxes use the *73-79* Pittman Arm as the the Arm is essentially the same from 56-72 (output shaft size is the same). The output shaft size on the TRW boxes are the HUGE ones that the 73-79 used. At least that's what it was when I last looked at one a year ago.