I just picked up a '96 disco with a 200tdi 5spd swap. Very fun truck so far but it started making a new noise yesterday. I'm trying to get all of these things addressed for my safety inspection.

The noise sort of sounds like a metal on metal squealing. I believe it's coming from the right rear corner (but not 100% sure, it's difficult to tell with just me in the car). It does not happen at idle, only when rolling. It does not really change with speed or RPM. It sounds the worst when slightly turning to the right. The noise goes away while turning left and under breaking.

Does this sound like a wheel bearing? Anything else I should be looking into?

 

I had a Jeep Grand Cherokee that did the same thing years ago. It was my wheel bearing. Under braking, the noise would decrease slightly as the rear axle was unloaded. When I turned left, the same thing would happen as weight was transferred off of the left rear wheel.

 

That was my thinking as well so I'll definitely look into it. I'm just confused because it's more of a squeal than the usual wheel bearing "hum". I just went for another drive and notice a couple of other things. The noise is just as loud at 5 km/h than it is at any speed. There is sort of a sweet spot (frequency I guess) at ~1800 rpm in 4th gear where it goes away.

 

Also, it seems like the noise is the worst when turning the steering wheel to the right from centre to a few degrees. I can make the noise come and go just by wiggling the steering wheel. This made me think power steering but it only happens while rolling and not while wiggling the steering while parked.

 

Have you worked on your brakes lately? Could be a brake pad.

 

Personally I haven't because I only just bought the truck. But I think you are right. That'll be the first place I look. Ruled out the wheel bearing because it makes the noise just as loud when the truck is just barely rolling