Standing on the shoulders of the giants on I8MUD, I have replaced the steering rack on a HDJ100 (that's an LC100 an 1HD-FTE diesel engine). My truck was built in 2004, so it has the newer design: no right hand grommet but bolts and nuts L and R to hold the rack in place:
Also, in this newer design, the "return tube" is a small piece of pipe with a clamped rubber hose, not the 'hard' line described frequently. I took the hose off, attached another hose leading to a waste container and started turning the wheel lock-to-lock. (And I noticed the wheel was off-center to begin with, which explained why the number of threads on the rack ends were not the same.) Turning the wheel will get half of the (old, black) ATF out (about 0.5 litres). The rest comes out of the reservoir, the pump and the lines while disassembling. I cleaned the reservoir and the lines. Next, I have centered the steering wheel and loosely attached it to the brake pedal using a piece of rope (the point was that I did not want the wheel to be able to turn too far with the rack out, leading to sprial cable trouble).
I could not remove the "no. 2 intermediate shaft assembly", nor the LH "tie rod end", nor the small pipe for the "return tube" (picture below is not accurate - that is the old design). I was able to slide the yoke a bit higher up the steering shaft, so I decided to remove the rack with stuck parts still attached.
I have loosened BOTH L/R engine supports and jacked the engine about 5 cm (2"), using the engine-gearbox joint as a lift point with a block of wood. This way, the jack was not in my way and I did not risk pushing the oil pan in. The 1HD-FTE has no problems with the shroud of the fan while lifted. With a bit of man-handling, the steering rack came out, parts still attached. Rust dissolver, a 2 kilogram hammer, a blow torch, patience and having the thing in a vise enabled me to remove the intermediate shaft and the pipe for the return line. Glad I decided to NOT try that under the vehicle. I have new tie rod ends, so I left the old one on the to-be-disposed rack.
The new rack (PartSouq, about US$1800, including tie rod ends and lock nuts) does NOT go in without lifting the engine again, whatever the FSM says, and I really tried. After loosely fitting the bolts, I measured the length from the end of the "rack end" to where the rubber boot attaches to the housing and made sure I centered the rack (distance was 275 mm both sides).
The sliding yoke in the steering column can be mounted in only one position, but while cleaned and lubricated, it can be slid up with ease, allowing the intermediate shaft to be positioned over the steering rack. After centering the steering wheel once again and attaching the intermediate shaft temporarily (installing the screw so it could not detach, making me loose position), I undid the rope on the steering wheel and turned lock-to-lock. From the center I get 360° plus about 225° turns either way (about 1⅔ turns, measured using masking tape on the 12 o-clock position of the centered wheel).
The gasket for the pressure feed (picture above) is a bit special and I could not find it; I replaced that with two new copper gaskets. I torqued everything up, but did not attach the ATF return line hoses. I plugged the tube coming from the reservoir and attached the tube-and-waste container to the small steering rack return pipe. After filling the reservoir with Dextron III, I turned lock-to-lock a few times, while keeping the container filled. I 'spilled' about 0.5 litre of good ATF, but I had no more gurgling sounds and I feel the same resistance in every angle of the steering wheel. (I did not want to start the engine to avoid having the power steering pump run 'dry'.) I used about 1,5 litres (quarts) of ATF for the whole procedure.
Next, I'll be putting the front differential (part of another project) back in and the rest back on. I'll update after the test ride, later this week!