For what it's worth... I think this is a thorough answer from an AI.

Prompt to Microsoft Copilot:
"Does a factory sealed wheel hub bearing assembly depend on preload torque?"

Short answer:
For a factory‑sealed, unitized wheel hub bearing assembly, the axle‑nut torque does not set bearing preload. The preload is built into the sealed unit at the factory. The axle nut’s job is different: it clamps the CV axle to the hub so the inner races stay fully supported and don’t move.

But—and this is the part that matters—incorrect torque can still damage the bearing, just not by changing preload.

🔧 Why preload is not affected

A sealed hub assembly (like on the LR3 you’re reading about) contains:

• Pre‑set, factory‑established bearing preload
• A fixed internal spacer
• Races that are clamped together internally

The axle nut does not squeeze the bearing together. It only pulls the CV axle’s splined stub tight against the inner race so the axle can’t move in/out.

So the preload is fixed and cannot be altered by torqueing the axle nut higher or lower—unless torque is so extreme that it physically distorts the hub, which would be catastrophic.

🔧 Why torque still matters

Even though preload isn’t affected, the axle nut torque is still critical because:

1. Too loose → axial movement → bearing failure

If the nut is under‑torqued, the CV axle can “walk” in and out slightly under acceleration/braking.
That movement hammers the inner race and causes:

• Premature bearing wear
• Wobble or vibration
• Gyroscopic loading (as one forum poster described)

This is a real failure mode.

2. Too tight → thread damage or hub distortion

Over‑torquing doesn’t increase preload, but it can:

• Stretch or damage the axle threads
• Distort the hub face where the axle clamps
• Make future disassembly miserable

This is why manufacturers revise torque specs—Land Rover lowered theirs to reduce premature failures.

🔧 So does a sealed hub “depend” on preload torque?

No — the preload is fixed at the factory.
Yes — the correct torque is still essential to prevent movement that destroys the bearing.

Those two statements coexist.

🔧 What this means for your original question

If a hub has been running at a higher torque (e.g., 258 ft‑lb) and you later torque it to the updated spec (e.g., 230 Nm / 170 ft‑lb):

• You are not “unloading” the bearing
• You are not harming the bearing by reducing torque
• You should torque to the correct updated spec
• Bearings do not “remember” the old load

The only thing that matters is that the nut ends up at the correct spec so the axle cannot move.

If you want to go deeper

I can break down the internal structure of a unitized hub, explain why preload is fixed, or compare how older adjustable tapered bearings differ from modern sealed hubs.

Would you like a diagram-style explanation of how the clamping load travels through the hub?