This is the second time I’ve seen the inside of an 80 series gearbox. I bought a used box this summer and rebuilt it with the help of a good friend and Lexus mechanic. Then we swapped it onto the truck in place of the original box, which was leaking from the input seal. Unfortunately, I managed to blow the input seal a couple weeks ago after mucking around with the adjusting screw. The leak was catastrophic, to the point where I had to park the truck because the system would pump itself dry on the trip to or from work. I ordered up a steering gear box reseal kit from Kerry (gotmud) last week, picked it up today and put the box back together tonight (I disassembled it last night). I figured that a full write-up was in order so I took many photos along the way. I sandblasted the box first which cleaned up the outside very well. I repainted the box once it was back together. I also only replaced one Teflon seal (at the bottom of the gear box housing), as they were a huge pain during the first rebuild and they don't seem to wear or age at all.
So without any further ado, on to the fun stuff!
Part numbers:
Toyota gear box reseal kit: 04445-60050
Power piston plunger guide nut: 44154-30020
Input shaft seal part number (not from Toyota See post #28): 18-32-7-DL
DISASSEMBLY
Step 1: Removing the pitman arm.
This was a challenge on both rebuilds, but a 20-ton press managed to pop the arm off (as well as scaring everyone else in the building!) after removing the 32mm nut. I don’t have a press at home, but I was able to get some help for that again this time.
Before:
After:
Step 2: Removing the sector shaft.
Start by removing the adjusting screw lock nut. A 17mm wrench and standard screwdriver are required here.
Note the seal washer:
Next, remove the side cover. Take out the four bolts holding the side cover on. I used a 14mm socket on an electric impact gun.
With the bolts removed, use the screwdriver to tighten (clockwise) the adjusting screw. This will push the side cover out of the box.
Nice needle bearing:
At this point, the sector shaft can be tapped out of the box with a soft-faced mallet
More needle bearings, and notice the power piston teeth in the foreground.
There is a seal, snap ring, metal ring, Teflon ring, and rubber O-ring in the bottom of the box. Remove them all, but leave the bearing in place. You may need to sand the corrosion off the box housing below the seal to allow you to get the metal ring out.
Step 3: Removing the worm gear valve body assembly.
Remove the power piston plunger guide nut. This should only require a 10mm Allen wrench, but in both cases I've seen it has required a cold chisel and some patience. I've listed the part number above as it is a cheap replacement.
Next, take out the four bolts holding the valve body head to the gearbox. I used the 14mm socket on my electric impact again.
Turn the input shaft all the way to the left. This will push the power piston to front of the gearbox. When it bottoms out on the front of the box it will start pushing the valve body out of the box. You can also use a screwdriver to coax it out.
This is the complete worm gear valve body assembly. Note the Teflon ring that can be replaced
This the metal tube that the ball bearings recirculate through (hence recirculating ball steering)
This worm gear moves the piston back and forth, which twists the sector shaft and pitman arm.
The inside of the gearbox. Don’t forget to replace the two little O-rings.
All the parts you have removed so far
Continued below...
So without any further ado, on to the fun stuff!
Part numbers:
Toyota gear box reseal kit: 04445-60050
Power piston plunger guide nut: 44154-30020
Input shaft seal part number (not from Toyota See post #28): 18-32-7-DL
DISASSEMBLY
Step 1: Removing the pitman arm.
This was a challenge on both rebuilds, but a 20-ton press managed to pop the arm off (as well as scaring everyone else in the building!) after removing the 32mm nut. I don’t have a press at home, but I was able to get some help for that again this time.
Before:
After:
Step 2: Removing the sector shaft.
Start by removing the adjusting screw lock nut. A 17mm wrench and standard screwdriver are required here.
Note the seal washer:
Next, remove the side cover. Take out the four bolts holding the side cover on. I used a 14mm socket on an electric impact gun.
With the bolts removed, use the screwdriver to tighten (clockwise) the adjusting screw. This will push the side cover out of the box.
Nice needle bearing:
At this point, the sector shaft can be tapped out of the box with a soft-faced mallet
More needle bearings, and notice the power piston teeth in the foreground.
There is a seal, snap ring, metal ring, Teflon ring, and rubber O-ring in the bottom of the box. Remove them all, but leave the bearing in place. You may need to sand the corrosion off the box housing below the seal to allow you to get the metal ring out.
Step 3: Removing the worm gear valve body assembly.
Remove the power piston plunger guide nut. This should only require a 10mm Allen wrench, but in both cases I've seen it has required a cold chisel and some patience. I've listed the part number above as it is a cheap replacement.
Next, take out the four bolts holding the valve body head to the gearbox. I used the 14mm socket on my electric impact again.
Turn the input shaft all the way to the left. This will push the power piston to front of the gearbox. When it bottoms out on the front of the box it will start pushing the valve body out of the box. You can also use a screwdriver to coax it out.
This is the complete worm gear valve body assembly. Note the Teflon ring that can be replaced
This the metal tube that the ball bearings recirculate through (hence recirculating ball steering)
This worm gear moves the piston back and forth, which twists the sector shaft and pitman arm.
The inside of the gearbox. Don’t forget to replace the two little O-rings.
All the parts you have removed so far
Continued below...
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