I’ve always had a slight whine in the back differential the amount of oil is fine. In fact, I made sure it was topped off before I left for my job yesterday so I assumed that my bearings needed to be replaced because I was hearing it’s a common issue.

 

So I went under the truck and moved around at the connection point between rear differential and the driveshaft, and I couldn’t get it to move in any direction.

 

Glad you checked the gear oil level and the play in the yoke area of the differential. Is the rear axle disc or drum brakes and how many miles is on the truck/rear axle? I did hear a bit of a whine from the video, but couldn't clearly make it out..

 

It has drum brakes and I’m assuming it’s the original rear end so about 177,000 miles

 

Bearings can still be noisy, even if they are tight. Also keep in mind, there are also bearings on the carrier, and out at the ends of the axles.

If the rear end whine is consistent with speed, that is likely carrier bearings, (or maybe axle....) if it is more pronounced under load, or coasting, then it is likely pinion bearings. Changing the front pinion bearing is easy..... changing the rear requires disassembling the entire axle.... and if you are going that far, might just as well replace ALL the bearings.

 

I’ve always had a constant whine in the back differential but that extra squeal noise is new and I want to say it’s probably more predominantly right side, but I don’t know that 100% I’m thinking maybe it’s the axle bearings?

 

Where the brake shoes changed recently? I ask, as sometimes the rear backing plate can rub against the drum and cause a noise as the truck is moving.

 

No, I haven’t changed them since I’ve bought this truck. I haven’t owned it for more than six months.Or so

 

Pull the cover off the rear diff, if you have the LSD rear, the clutch retainer clips like to fall out, get jammed up in odd places, and can so some serious damage. A quick look certainly won't hurt, and isn't expensive.

 

OK when I get a chance, I’ll see about pulling the differential cover and taking a look

In the meantime, I pulled both of my drums off and there appears to be a good amount of material left on the shoes but it did only appear on the left side that only the left shoe would only be pushed out by the hydraulic. I don’t know if it’s supposed to push both out at the same time on this, but it was just something I noticed. It’s been a while since I’ve worked on. Drums