If you have a pre 1980 LC 40 model you will probably not have power steering. Adding that is one of the better upgrades you can do, in addition to disc brakes in front.
Original 40 power steering can be found, but they are a bit underpowered, and the steering will still be imprecise due to two additional joints with the relay solution.
A better solution is to use power steering from a newer LandCruiser, such as 60, 70 or 80, or from Hilux/mini truck. These will allow you to remove the relay unit. But check that the pitman arm is in correct position as this can vary between models and years. In the US also Saginaw boxes are popular as they are easy to find. They are technically working fine, but in my opinion not looking good as the box is very visibly sticking out in the front. A LC box on the other hand looks nearly original in the way it fits in.
The power steering I used for my project comes from a LS 70, but could as well come from one of the other cruisers mentioned. These steering boxes are nearly the same. The steering rod and the pump are also from the same 70. This is fitted to a B diesel, but except for fitting the pump the work will be the same on a petrol engine.
Read more Land Cruiser 40 related here: land-cruiser-40
Click on any picture to start slide-show.
Steering Box
First I found the best position for the steering box. The damper tower has to be modified to allow for the steering shaft to pass by. I removed the tower and put a 10 mm steel plate between frame and tower to avoid removing to much of the tower.
Finding the right position. Notice the removed damper tower.
Using a simple jig to assure drilling straight through
You must weld a plate on the inside of the frame. 5- 6 mm would be fine . Also use pipes inside the frame for the bolts to avoid warping the frame when tightening up the bolts.
Cutout of damper tower. Notice 10 mm plate between tower and frame.
Steering shaft
The steering shaft also comes from the 70. You will need the lower part of it, with two u-joints. It has to be cut and welded onto the 40 steering column which also must be cut. The joint will be inside the tube around the column. The two parts fit perfectly, 40 solid column inside the 70 tube. Assure a good weld here… You will also get a bit more security as the 70 steering shaft is telescopic and collapsible. Also the firewall bracket comes from the 70.
The welded steering shaft
40 shaft to right, 70 to left. Need a good weld here
Steering rod
The steering rod can be a problem as the 40 rod is to short, and 40 use 12 mm bolts while the 70 (and 60 and 80) use 14 mm bolts on the ball joints/ tie rod ends. I decided to use the 70 rod and drill up the hole in the 40 steering tie rod to 14 mm. The 70 steering rod is too long and must be shortened.
Tools needed for steering rod: a conical drill bit and 23×1.5 mm thread tool, left and right threads. All ordered from China/ eBay at a very reasonable price.
40 steering/tie rod connection and 70 end. The tapered hole in the 40 TRE must be drilled up to 14 mm.
70 to left, 14 mm. 40 is 12 mm
And finished, with 70 steering rod and ball joint.
Pump
I used the 70 bracket to fix the pump to the engine. Had to cut off a part and make another bracket of flat steel that was screwed onto the block with some distance tubes, using the oil pressure outlet from the block and two other holes. I will be relocating the pressure switch to the same place as the pressure sensor. The wooden 2×4 piece is used to find correct distance from block, around 4.5 cm.
Reservoir
I made a bracket for the 70 reservoir on the side of right battery tower. This also means that the air filter must be moved 5 cm to the rear. Made a bracket on the fender for that.
New bracket for air filter on fender, moved 5 cm to the rear.
Battery tower
Left battery tower (24 Volt on this) cannot be used or modified, so I made a new. See also picture in top.
Radiator frame and fender
The radiator frame and fender must be modified a bit to give place for the box
Read more here: land-cruiser-40
