Hilux wheel bearing or diff whine?

[lortap1]

Hi all

I have a 96 4x4 hilux. I have a rear end whining noise that appears at around 70km per hour and increases in volume the faster i go. The noise is there only under load (i.e. no noise when freewheeling). The noise is there in all gears, suggesting it is not the gear box. Other posts on this forum suggest it is either the diff or rear wheel bearings.

The question is how do i diagnose whether it is wheel bearings or diff?

From what I understand rear wheel bearings in hilux's are sealed units that sit half way along the drive shaft. Presumably that means it is not possible to do the normal jack up and shake wheel test?

Any help would be greatly appreicated.

Cheers

[chunks]

Get up to the speed that it starts making the noise, then just put the clutch in and let the car roll. If the noise goes away once you take the drive out of the equation its more than likely a noisy crown wheel and pinion. If the noise stays regardless of whether the clutch is in or not then have a look at the wheel bearings.

[RAY185]

From what I understand rear wheel bearings in hilux's are sealed units that sit half way along the drive shaft. Presumably that means it is not possible to do the normal jack up and shake wheel test?

Not half way along the axle. They are a semi floating diff so the bearings are sealed units that sit on the axle inside the end of the axle tube just behind the brake backing plate. Jack up/shake wheel test should still work but no feeplay doesn't necessarily mean the bearing is not noisy.

[borgy11]

I just got my diff done in my lux, i had many different noises.
growling when slowing to a stop
a high pitch sound when i got off the accelerator from about 60 km and a bit of shudder on take off.
i got the lux test driven by a diff repairer and he told me a few things and showed me a few things also.
if the noise is still there in fourth gear then its prob not the box
when you get up to the speed the noise happens start swerving from one side of the road to the other. obviousley use a quite road and don't go to hard on the wheel or you'll go shiney side down.if the noise changes or goes away as the wheels are loaded then this is a good sign of dodgy wheel bearings. i had a worn pinion bearing due to the crushable spacer squeezing up and got a solid spacer put in at extra cost plus the pinion bearing replaced etc. also check the big nut behind where the tailshaft bolts on.
something else to think about is centre bearing or uni joints.
hope this helps.

[lortap1]

Thanks for the suggestions. I will look into it a bit further and post once i have confirmed the problem. Sounds like it might be worth taking it to a diff expert.