Do people typically replace rear axle bearings when changing oil seals or is it generally unnecessary?

The truck has 123K on it and has never been driven hard. All city or highway driving. Judging from the work I had to do on the front end though, my friend was not afraid of potholes or rough roads.

How does one know if the bearings need to be replaced? What should I look for?

Thanks. Not much experience with rear ends. Haven't pulled an axle in 25 years. I'm sure things have changed a bit.

I ordered the new bearings already with the seals and the diff cover, and have access to a puller. I'm just wondering if I shouldn't just hold onto them for later work, or if it's one of those "..while you're in there..." things.

 

Pull the axles and look at them. If the bearing surfaces on the axles are smooth and of course the bearings look ok, I wouldn't replace the bearings. The axle bearing surface will fail before the bearing I suspect because it is softer metal. Axles have to have high tensile strength and that makes them softer than the hard rollers in the bearings.

 

You definately should replace. The extra $100 is worth it.

 

Earlier this year my 02 truck had a bearing roar in the right rear. I pulled both rear axles and looked. The right rear axle bearing surface was pitted and the bearing looked fine. I replaced the axle and bearing and seal. The left side axle and bearing looked perfect so I reinstalled the LR axle and bearing replacing only the seal. After also replacing the RF bearing hub, my truck is quiet as new.

 

My experience has been if the seal is leaking, the bearings and/or axle shafts have excessive wear. Generally it's just the bearings. The few times in the past that I replaced only the seals, the leak returned.

It's better to know the job was done right. It wouldn't be fun to throw away that expensive synthetic gear oil and do the job twice. Replacing the bearings is pretty simple with the right tools (a bearing driver set and slide hammer, which can usually be rented for free at Advance or AutoZone if you don't own them).

Just my 2¢

 

The more I think about it....... since I have the new bearings anyway, and I'll be in that far, might as well replace them.

Thanks for the input. I'll post results.