Harmonic squeal when hubs NOT locked (1 Viewer)

[simps80]

I have a high pitch harmonic sound when moving (no sound when not moving).

the interesting thing is I just removed drive plates and put on selectable hubs.

the sound only happens when the hubs are unlocked and goes away when locked (which correlates to no sound previously with drive plates).

it would make total sense if it was the other way around, noise when hubs locked, but it makes no sense to me when hubs are unlocked.

many ideas in what would make a high pitched harmonic in motion noise in 2wd?

this is with the transfer case in 2h by the way

Here is a picture just to break up the word wall of the new hubs I just put on.

 

[1969FJ]

I see where your concern is. The drive plates had no engageable/disengageable parts in them, hence no squeak. Perhaps those new hubs are doing it as you drive. Even though 4HI is not in on transfer, there still is movement from the differential , but not under power. Did you check your fluid level in the differential, and the axle birfield seals ? Try locking the hubs in 4x4 without engaging the transfer case and see if you still squeak.

 

[simps80]

Yes that’s the weird thing
With the transfer case in 2wd and the hubs in 2wd is when the noise happens.

with hubs in 4wd no noise

makes no sense

less stuff is turning with hubs in2wd and transfer in 2wd

 

[1969FJ]

Yes that’s the weird thing
With the transfer case in 2wd and the hubs in 2wd is when the noise happens.

with hubs in 4wd no noise

makes no sense

less stuff is turning with hubs in2wd and transfer in 2wd

Actually, you can close in on the issue. When the FJ40 is driving, no 4wd either hub or transfer, the axle is still rolling. It does not take much for a squeak as you have said. My opinion is to perhaps pull the hubs and lube them. Squeaking can be less than you think. Think of brakes. My call is the hubs.