40-series Power Steering Gearbox SST's & Rebuild

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Adjust The Cross Shaft Adjusting Screw

1. Measure the thrust clearance of the adjusting screw.

Clearance 0.03 - 0.05 mm (0.001 - 0.002 in.)​

2. Unstake the lock nut.
3. Loosen the lock nut with SST. SST [09630-22010]

4. Adjust the clearance of the adjusting screw by turning the lock nut.
5. Stake the lock nut.

Here's a closeup picture of the SST mentioned in steps 3, 4 & 5; The OTC part number for the Hex Wrench is [0002-00805].

 

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Power Piston Nut

1. Inspect the following for damage or wear.

• Cross shaft gear tooth contact surface
• Teflon ring
• O ring groove

The gasket kit [04445-35040] comes with three large O rings seen here in the top row (greatest to least thickness respectively from left to right). The O ring matching the thickness of the original one shown in the lower left is the one having the greatest thickness of the three from the kit.

Here I've replaced the O ring and teflon ring on the power piston. The middle O ring pictured above was utilized in combination with the teflon ring for the power piston. The O ring pictured above to the right will be utilized on the end cap when the cross shaft is assembled with the housing.

2. Measure the ball clearance.

Clearance

STD 0.02 - 0.06 mm (0.0008 - 0.0024 in.)
Limit 0.15 mm (0.006 in.)​

 

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Adjusting Plug & Worm Bearing

1. Support the valve body by installing it to the gear housing.

2. Remove the lock nut with SST [09630-22010].
3. Remove the adjusting plug with SST [09630-22010].

4. Inspect the following for damage or wear.

• Oil Seal
• O ring contact surfaces
• Bearing

Installed a new oil seal using the OTC seal installer [00002-00808]. The SST has a stepped face that fits in the back of the seal. The gasket kit comes with a new oil seal having the markings, NOK AP8096E 164

5. Install the adjusting plug provisionally.

• Use a new O ring.
• Install the bearing.

Here's a closeup view of the new O ring installed into the recessed seat. The old O ring had become brittle and hardened to a flat surface of the inner diameter.

 

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• Install the adjusting plug provisionally with SST [09630-22010].
• Remove the valve body and the power piston nut from the gear housing.

Gear Housing
Inspect the following for damage or wear.

1. Needle roller bearing
2. Teflon ring
3. Dust seal

After removing the dust seal, snap ring & steel ring, here's what the old Teflon ring looks like. The Teflon ring sits inside of another O ring and requires an SST to be installed properly.

The new power steering gearbox housing came with the needle roller bearings pre-installed. The gasket kit doesn't come with any bearings. The markings on the bearing, NTN 7E-HMK 3230 JAPAN FU can be seen in the following picture. I found the manufacturer, NTN has 7E-HMK3230 listed for the part number.

Installing the teflon ring and O ring was a pain even with the bearing replacer. I lubed the O ring and inner surface of the housing with ATF fluid to help slide things into place. Here's a shot of the O ring, teflon ring, steel ring & snap ring installed.

 

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Replace the Needle Roller Bearing

1. Remove the dust seal with a screwdriver.
2. Remove the snap ring. (The FSM doesn't mention removing the steel ring that sits behind the snap ring)
3. Remove the teflon ring.

4. Remove the needle roller bearing with SST [09630-30041]

5. Install the needle roller bearing with the longer edge of the outer race facing outside.

6. Install the needle roller bearing so that it is positioned 23.6 mm (0.93 in.) away from the housing end surface with SST [09631-60010]

The new power steering gearbox housing came preinstalled with the needle roller bearing indicated above. These steps were unnecessary for my rebuild; however, I thought I'd include it in the thread for those requiring a new bearing.

 

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Installing the Teflon Ring

7. Install the teflon ring together with the O ring to SST [09631-60010]

8. Install the teflon ring and the O ring to the gear housing with the SST [09631-60010]

9. Install the steel ring and the snap ring. Confirm that the steel ring can be turned by hand.

10. Rub SST along the inside of the teflon ring so that it will fit smoothly over the cross shaft.

 

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Here's a shot of the OTC seal replacer.

 

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11. Install the dust seal with SST [09631-60010]

The dust seal included in the gasket kit was enclosed in its own plastic bag and had some sort of lubricant applied on the inner rim of the seal. The markings on the seal: NOK AG1862E 25

 

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Assembly
Assemble the parts in the numerical order shown in the figure.

 

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Fit the O ring accurately.

This step gets a bit tricky, the Teflon ring needs to slide past the sharp edge within the housing to be seated all the way. If you’re having difficulty, I’ve been able to use the rounded side of a dental pick to tuck the Teflon ring while gradually working the valve body into place.

 

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Tighten the bolts diagonally and evenly in two or three rotations.

 

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Tighten the valve body.

Tightening torque 4.0 - 5.5 kg-m (29 - 39 ft-lb)​

 

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Adjust the preload of the worm shaft.

1. Tighten the adjusting plug with SST [09630-22010]
2. Turn the worm shaft to check the turning condition.

 

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3. Loosen the adjusting plug with SST [09630-22010] to adjust preload.

 

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4. Insert SST [09630-22010] into the serrated section of the worm shaft, and measure the preload with a torque meter.

Preload (starting torque) 4.0 - 6.5 kg-cm (3.5 - 5.6 in.-lb)​

- Note -
Hold the power piston nut to prevent it from turning.

Here's a close up of the SST and section of the worm shaft referred to in the FSM passage above. Observe how the OTC worm bearing socket [00002-00811] is alligned on the serrated end of the worm shaft and the flat portion of the shaft.

 

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5. Tighten the lock nut with SST [09630-22010]

Tightening torque 4.5 - 5.5 kg-m (33 - 39 ft-lb)​

 

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6. Recheck the preload.
Check to see that both the right and left rotations are identical.

 

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Wrap vinyl tape around the spline area of the cross shaft and loosen the adjusting screw fully.

Align the cross shaft gear center with that of the power piston nut gear.

 

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Never turn the cross shaft, as this may cause O ring damage.

Tighten the end cover diagonally and evenly in two or three rotations.

Tightening torque 4.0 - 5.5 kg-m (29 - 39 ft-lb)​

 

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Adjust the cross shaft preload.

1. Set worm shaft to midpoint position. Determine total number of the worm shaft turns and return from full lock by half that number.

2. Insert SST [09616-00010] into the serrated section of the worm shaft.
Turn the adjusting screw, and measure preload with a torque meter.

Preload (starting torque)
Worm shaft preload plus 2.0 - 3.0 kg-cm (1.8 - 2.6 in.-lb)​