New Adventure: Replacing the Rear Axle Beam

Thus begins the next phase of getting our 2011 Gen 3 into significantly better shape.***

I've made good progress and will write about that in a bit. At the moment I can see I'm going to soon be challenged by:

1) I absolutely need to have a proper 10mm "union nut wrench" (aka flare nut wrench), so it's off to the store tomorrow. I was able to release the brake line nuts without it on the replacement axle (I don't care about those lines: they simply chopped them off removing the axle from the parts-car.) ... but not so easy on mine. I do NOT want to round off the hardware.

2) A clip I've never seen before and had to break just to make progress. QUESTION: Does anybody have experience with this? How are you supposed to remove the clip part, and now that the clip is busted, do I need to replace both the clip and base, or ???

The P/N is 90467-17026-A0 (base) and 90467-17027-C0 ("clip")
Not costly, but oh what a pain, at least for me who has never dealt with this kind before. Here's a pair of before-after photos ('before' is actually halfway through breaking it to bits...)
This is located on the "rear floor side member cover" right side (L side is completely different ), P/N 57627-47010. This same clip is apparently in one or two other places. It is quite large and strong. About a one inch standoff.



Any insights most welcome. I need to get that fixed before final assembly is complete.

3) The replacement axle has some rust, as does my current one. I'm thinking I will:

• Wire brush any loose paint, any visible rust
• Brass spin-brush rust down to bare metal
• Use good quality rustoleum rust converter primer and paint to clean it up

And then??? Is there any coating worth applying that would resist road-rocks etc? We don't have salt here in the mountains, but we do have liquid magnesium chloride and sand on roads in winter.

THANKS!!!

*** For those who are new to this saga...

• My sweetie is a nature photographer. We take long trips, stopping at most of the brown signs along the way (National Parks, Nat'l Wildlife Refuges, etc). So, our 2011 Prius has 230k miles.
• As is common, after about 100k miles, oil started to disappear, eventually hitting a quart per fillup.
• And I learned how to properly maintain and replace HV battery modules...
• Then a couple of years ago in the heat of summer while visiting the LRGV (Lower Rio Grande Valley, on the south border of TX), all hell broke lose. Obvious head gasket going bad.
• Miraculously, a patch job helped us survive another 1600+ miles.
• Amazing friends combined to give a Christmas present covering the $4k+ cost of a complete engine replacement. While working on that, sadly I bumped a curb in an ice storm (here at 7000 ft in Colorado.) Got the R Front hub/wheel replaced quick, in time for us to...
• DRIVE (!) to Knott and Orangethorpe (Buena Park CA yes near Knott's Berry Farm!), eat good food at Paul's Place, and hang out a bit while new friends at Hybrid Pitstop did a 100% complete engine replacement and more in literally one day.
• Over the summer of '23 I learned to fully replace the front bumper cover, learned how to match paint (English Color ECS is your friend), and also got a new front clear bra. This car is looking good and driving fine! 60 mpg driving to Denver yesterday... although net only 45mpg round trip.
• Unfortunately, I also have learned that the curb-bump put the rear alignment out... permanently. Shims didn't help. New hubs taught me a lot but didn't fix it.
• After too much effort, I now have a replacement rear axle beam ready to install, courtesy of Central Auto Parts in Denver. Only $US160 plus tax, customer pickup so no shipping charge.

 

[UPDATE: I gave up. Clearly these are defective. Ordered OEM from my local dealer. I *need* this car working. Parts arrive Monday.]

Was about to enjoy full success... and ran into what feels like a tough problem. I don't see how the replacement bushing can fit into the ring... bushing diameter is 1mm larger at one end, 2mm larger at the other. Do you just use a super-heavy press to jam it in? I am using a VERY powerful ball joint press (Autozone 57023) and it's going wayyy past the 150lb mark on my breaker bar / gross torque wrench.

I suppose I could rent a 600lb breaker bar but this feels like overkill...

 

A couple of updates. Hopefully my next post after this will be a How To on getting the job done.
1) The downhill slide in supply chain is hitting Toyota as well. I went in to pick up the parts...and they were not only not-there, but back ordered for who-knows-how long. ... I canceled the order, reinstalled the old axle, and we drove to Arizona. Car worked great! Probably burned some extra tire tread, but oh well. I now have the correct / low cost bushings. Still from Rock Auto but Delphi TD1978W. My measurements say they ought to fit much better. We will soon find out!

2) I worked out what's up with the "clip." I would call it a plastic bolt although I can see why they call it a "clip." Here's what is up:

a) Here are the two parts involved. 90467-17026-A0 and -17027-C0.

• Look closely at the -C0 (black) part. Inside, it has two flex sets of prongs. These allow it to be pushed on but must be unscrewed to remove. By unscrewing it easily comes off, otherwise you WILL break it.

• It was very very hard for my dealer to find a diagram and the above part numbers. Toyota's database has a few errors in this realm. In fact, when I searched online, depending on the path taken I was told this part is not compatible with my Gen3 Prius! Crazy. The same part is used in two or three places to hold the under-covers.

b) Here's the complete diagram for ALL Gen 3 (2011) bottom covers. I've also uploaded the SVG file below, which has highlightable links for every P/N.


c) Here's the service manual instructions for removing the "rear floor side member right hand" that includes this "clip." (it's in the dotted triangle.) Singularly unhelpful. And this "clip" is not at all listed in the service manual overview instructions for clip handling.

Hope this helps someone!

 

Papa Pete’s How To on Prius Rear Axle Beam Replacement
Introduction
What?
This is a pretty significant repair/maintenance project. It involves at least the following:

• Remove/replace rear hubs/bearings
• Disconnect/reconnect rear brake calipers and lines (and drain/refill brake fluid)
• Disconnect/reconnect and adjust parking brake
• Disconnect/reinstall rear springs, and lower end of struts
• Disconnect/reconnect rear ABS sensors (and recalibrate)
• Install new axle beam, and a pair of bearings to go with it
• Remove/replace several other parts

I’ve supplied excerpts from the service manual for all of this (thanks, Mendel ). So yes, there are hints here on how to do all of the above, plus tools needed, torques and socket sizes, and more.

Why?
I learned the hard way that many modern small cars use a solid rear beam axle. It performs well, and is relatively low cost. However, there’s one major challenge: if you bump a curb a little too hard, you get to replace the entire axle.
With this design, there are no adjustments of any kind. The rear wheels are completely non-alignable, other than using pretty wonky shims for small adjustments. (I tried that on mine; it never was close. AND, a mechanic friend pointed out that even a small bend in the axle weakens it, making it dangerous in a future accident.)

From here, I'm just going to include a few attached files. There is too much formatted content to convert to BBCODE

 

Since none of the content of my tutorial will be indexed by PriusChat, here's a table of content for the first document I linked...

Overview
Parts Needed and Sources
Tools Needed and Handy (including what to get on no-charge loan from AutoZone)
- Includes details on tools to remove and install the large axle beam bushings
Summary: Torques and Sockets (I repeat this section below. Just seems handy for lots of reasons )
Notes on detailed project steps. Includes photos, video tutorial links, etc. Includes
- Disabling brakes
- Releasing and adjusting parking brake
- Remove / reinstall parking brake cable
- Remove / reinstall rear suspension brace
- Remove/reinstall rear hub/bearing
- Disconnect / reconnect speed sensor wire from rear hub
- Remove/replace rear springs, lower end of rear shocks
- Disconnect / reconnect / flush rear brakes, bleed brake lines
- Remove / reinstall rear axle beam
- initialize and calibrate linear solenoid valve
- stabilize suspension
- yaw rate and acceleration sensor calibration
- Index to service manual pages for all of the above

What a great chance to learn many car systems :-D


Torque and Socket Summary
These torque specs can be found in the service manual component diagrams, detailed instructions, etc. Socket sizes were collected as I did the project . A few items have no specified torque.

• Wheel Nuts 21mm, 76 ft-lb
• (Inside) Lower Instrument Panel Finish Panel Assy screw, 10mm
• (Inside) Parking Brake Cable adjusting nuts 2x10mm. Need a thin wrench.
• Rear Floor Side Member Cover LH/RH bolts/nuts 10mm, large Phillips screw “clip”
• Rear Suspension Brace SubAssy bolts 14mm (40 ft-lb), plastic nut 12mm
• Rear Speed Sensor Wire mount nut 10mm, 75 in-lb
• Parking Brake Cable Assy remove 3 mounts first (bolts 10mm, 53 in-lb), then release w/ 14mm closed end wrench
• Disc Brake tubes: mount bolts/nut 10mm, 14 ft-lb; tube connector 10mm flare nut (11 ft-lb)
• Disc Brake Caliper Assy bolts 14mm, 42 ft-lb (25 ft-lb for caliper/slider bolts)
• Disc Rotor—if stuck, use M8x1.25 bolt in the built-in screw holes to force it off
• Axle Hub/Bearing bolts 14mm, 66 ft-lb
• (Rear Wheel House Liner; Height Control Sensor) – I don’t have these
• Rear Shock Absorber Assy, nut and bolt 17mm, 66 ft-lb (threads/nuts toward outside)
• Rear Axle Beam Assy, bolt 19mm, 100 ft-lb

 

The service manual says to drain and refill.

My hints include my revised sequence... and while I did do a complete flush and drain the first time (because it needed a flush anyway), since then I did NOT.

To do a proper job on axle beam replacement, it's impossible to take care of the brake lines without any fluid loss, because the brake lines go through a few mounting points on the axle, and have to be at least briefly disconnected. But if done carefully (and still releasing all pressure before starting), it can be done with only a few ounces of brake fluid loss.

Basically, I disconnect the caliper (gotta do that to get the hub off the axle).. then release all the brake lines from the axle, and reconnect them as I go. I was able to arrange it so the caliper was on the ground out of the way while I pulled the old axle and put the new one in place.