Replacing Rear Bearings - what ancillary parts should be replaced?

Looking over this nicely detailed thread about replacing the rear bearings, there is a parts list of secondary parts that the author decided to replace:

9020844001 – Belleville washer for axle shaft, qty 1 for each bearing
[$4.76] (https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-washer-9020844001)

9052041019 – lock ring, qty 1. For each bearing
[$2.93] (https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-hub-and-bearing-snap-ring-9052041019)

4242360050 – seal retainer, qty 1 for each bearing
[$22.29] (https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-retainer-4242360050)

9031058003 - Drive Axle Shaft Seal, qty 1 for each bearing
[$7.99] (https://toyotaparts.mcgeorgetoyota....ve-axle-shaft-seal-left-right-rear-9031058003)

9030183002 - Hub & Bearing O-Ring, qty 1 for each bearing
[$3.75] (https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-hub-and-bearing-o-ring-9030183002)

90114A0009 – bearing case serration studs qty 4 for each bearing – I ordered 8 to replace both sides
[$1.60] (https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-bolt-serration-90114a0009)

90178A0052 – bearing case nuts qty 4 for each bearing - I ordered 2 extras in case I damaged one or lost one while pounding off the old studs.
[$1.32] (https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-strut-mount-nut-90178a0052)

4704404030 - Brake Backing Plate (Left, Rear)
[$83.25] (https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-backing-plate-4704404030?c=bD0xJm49U2VhcmNoIFJlc3VsdHM=)

4704304030 - Brake Backing Plate (Right, Rear)
[$83.25] (https://toyotaparts.mcgeorgetoyota.com/oem-parts/toyota-backing-plate-4704304030)

Question: Which of these are likely needing to be replaced? I'm guessing the axel seals and the O-Rings. Unless something gets broken or damaged on removal?

In the DIY videos I've watched it seems that the old parts are in good condition and are re-used in most cases.

 

One video I found the guy referenced "new" studs ... is it advisable to go with new ones or should the old ones be reusable?

 

TO ME, I don't think you need to replace the backing plate unless there's a problem with the old one. They are REALLY robust. I had to replace my right side when I did mine because the old bearing retaining bolts were so corroded into the bearing assembly, I had to use an angle grinder to cut through the bearing assembly. I thought I was good, but discovered when I was trying to pound the bolts out (before I decided to cut), I warped the plate - before I cut it with the angle grinder, I had used a 9x rivet gun to try and pound the bolts out...didn't work

I did replace that cheesy paper gasket that goes on the flange of the hub (before you mount the brake drum) just because I was doing all that anyway, and they are cheap, but many don't bother and just put anti-seize on the flange.

 

You don't need to replace the backing plate unless there's something majorly wrong with it. The only wear issue is possibly from the brake shoes dragging on it- mine were fine. I replaced all of the hardware when I did mine as I posted in that thread. You are supposed to change the pressed collar per the Toyota FSM. IIRC, I measured the ID of the ones I removed, and the new replacements, and there was no difference in the ID; I'm sure most people reuse them. Buy new o-rings and seals. What hardware you can reuse depends on the amount of rust. If you want to save $, then try to loosen all the nuts before you order parts. If they break free, you're good to reuse. If you knock out the studs, I'd buy new ones, and then you might as well also get the nuts.

 

Yup, all good, don't bother with backing plates.

If you're going OCD, the brake cylinder makes more sense than the backing plate.

Also, check your parking cable to backing plate housing, they crack and if you feel really ambitious you can change it as well.

 

So the mechanic's answer was, when replacing the bearings you also need to replace:

• retainer
• snap ring
• maybe studs / bolts
• axel seal
• o-ring

 

based on my experience your list is good but the snap ring can likely be reused.