Rotted out rear end

[Billiam]

As some of you know....the Yaris is susceptible to severe corrosion where the rear trailing arms and beam are welded. This can eventually lead to complete failure and collapse of the rear suspension. Thankfully I notice the severe lean-in of the left rear tire on my daughter's '10 Liftback before something potentially tragic happened.

Forget finding a new one. There are none in The States. In fact, there's a national back order. I was able to locate 4 rear ends from various salvage yards. Unfortunately they were rotted out as well.

After cross referencing the OEM part number I realized the same rear end is also used in the Prius C and the Scion xD. I was able to expand my search now. I got lucky and found a clean xD axle, with little to no corrosion.

She's now back on the road now. Just thought I would pass this info along in case it's not well known.

[Billiam]

https://youtu.be/dSqYi38AQmE

[sh0rtlife]

got pics of the rust????

i dont live in a salt state thankfully but id really like to see it so i know where i should look to apply some rust prevention..

[Billiam]

Mine looked exactly like the one in the video. These things rot from the inside

[sh0rtlife]

ugh i hate vids, anyone got pic's?..if they rust from the inside out it sounds like there must be a hole in em somewhere, need to coat the insides to prevent it

[Billiam]

ugh i hate vids, anyone got pic's?..if they rust from the inside out it sounds like there must be a hole in em somewhere, need to coat the insides to prevent it

Just click the link. It's a video from YouTube

[IndestructibleYaris]

That's scary, time to check mine and maybe reinforce.
I caught some paint bubbling and brown spreading under the sedan rear seat drain plugs on either side of where the fuel pump service door is. Youtube comments say the subframe and steering rack and pinion mount bolts rust off

[Billiam]

...need to coat the insides to prevent it

Before I installed it I cleaned and coated the entire new beam in POR15. After that cured, I filled the inside trailing arms with Liquid Wrench Rust Inhibitor, let it sit for a day and filled them again. And just the other day I pulled the rear wheels, shot more Inhibitor in the arms and applied all around the exterior welds.

I refuse to let what happened this past spring happen again.

[sh0rtlife]

i inspected mine when i did the rear brakes and honestly couldnt find any signs of issues..in fact if you told me the car was under 5 years old id belive you...so i suspect its a rust belt thing and nothing those of us outside teh rust belt even need to worry about

[Billiam]

i inspected mine when i did the rear brakes and honestly couldnt find any signs of issues..in fact if you told me the car was under 5 years old id belive you...so i suspect its a rust belt thing and nothing those of us outside teh rust belt even need to worry about


Though we do get some snow from time to time....I don't live in the rust belt

[sh0rtlife]

where abouts are you? any chance the car spent some time on salted roads?

i know the 07 ive got has barely over 100k on it and has only spent time in BC and oregon with some runs inbetween obviously.....honestly im suprised that living on vancouver island didnt cause a bunch of rust with the se salt air

[Billiam]

where abouts are you? any chance the car spent some time on salted roads?

i know the 07 ive got has barely over 100k on it and has only spent time in BC and oregon with some runs inbetween obviously.....honestly im suprised that living on vancouver island didnt cause a bunch of rust with the se salt air

I'm the 2nd owner. It has spent it's entire life in Central Ky

[Billiam]

I could kick myself for not taking better pictures of the old rear end. Unfortunately this is all I have and it doesn't show the actual separation of the beam and trailing arm. All you really see is the rust and dirt that fell out.

[sh0rtlife]

so it sounds like its a rust from the inside out kinda thing eh..if thats the case we all should pull em and hose the insides down with a combination of things..my goto in this case will likely be "zero rust", having used por15, eastwoods version and a few others..the zero rust is just as good at a fraction of the the costs...especialy on "internal" unseen stuff

por and eastwood both end up with better "seen" finishes while the zerorust is designed for "equipment and trailers" where abuse taking is more important than finish quality

[Billiam]

Yes...they rot from the inside out. Don't be fooled by looking at the outside and thinking things are fine. Every time I rotated my tires, adjust brakes, etc I always checked things out. It never occurred to me that anything was wrong. It all looked fine. It wasn't until it actually broke that I realized there was a problem that had been lurking internally....probably for years.

[Calrenman]

I had a 20 year old Geo Metro and was about to spray the green oxide inside the frame channels and kick boards. I crunched the car before I did the frame coatings. It was a shame the car had a full urethane suspension abd big swaybars. It handled like it was on rails in the canyons here in L.A. / Ventura counties. Hear is a link to the interior frame coatings.


https://www.eastwood.com/eastwood-internal-frame-coating-14oz-aerosol.html

Yes...they rot from the inside out. Don't be fooled by looking at the outside and thinking things are fine. Every time I rotated my tires, adjust brakes, etc I always checked things out. It never occurred to me that anything was wrong. It all looked fine. It wasn't until it actually broke that I realized there was a problem that had been lurking internally....probably for years.

[Billiam]

I had a 20 year old Geo Metro and was about to spray the green oxide inside the frame channels and kick boards. I crunched the car before I did the frame coatings. It was a shame the car had a full urethane suspension abd big swaybars. It handled like it was on rails in the canyons here in L.A. / Ventura counties. Hear is a link to the interior frame coatings.


https://www.eastwood.com/eastwood-internal-frame-coating-14oz-aerosol.html

That's very similar to the Liquid Wrench Rust Inhibitor that I used. The problem is, dirt and debri accumulate in the trailing arms over time. That material tends to get wet and stay wet. The corrosion will always effect the weak points first....that being the welds. So if someone is going to apply any type of rust inhibitor to the inside of the trailing arms I suggest they rinse them out thoroughly first and let them dry for a couple of days

[kobe52]

good headsup.

do you have a part number/s for the scion replacements?

[Billiam]

good headsup.

do you have a part number/s for the scion replacements?

4211052332

[IndestructibleYaris]

The only thing to prevent rust is oil or waxy oil spray. Think waste oil, woolwax, fluidfilm(smells like crap), etc. Never use paint or rubberized undercoating unless you're religiously using oil or wax overtop of it. Coming from an undercoating shop

[Billiam]

The only thing to prevent rust is oil or waxy oil spray. Think waste oil, woolwax, fluidfilm(smells like crap), etc. Never use paint or rubberized undercoating unless you're religiously using oil or wax overtop of it. Coming from an undercoating shop

I wired brushed the exterior portions of the trailing arm welds then applied 2 coats of POR15 to them. Once that cured I flooded the inside of the trailing arms with Liquid Wrench Rust Inhibitor and let it sit for a day. Then I flooded them again the following day. After I installed the beam I took a foam paint brush and coated the exterior welds with the LiquidWrench. I do that every few months.

I'm going on 2 years since the axle replacement. Solid as a rock so far. My 16 year old inherited the car a few months ago. I'm confident the rear axle will out live his stint with this vehicle.

As for the paint application? POR15 isn't exactly your garden variety stuff. When applied correctly it's an excellent barrier against corrosion. I applied 2 coats to ensure there was zero opportunity for moisture to find it's way passed it. Besides...the exterior welds aren't really the issue. It's the debris that gets trapped inside the trailing arms. Once it reaches a certain level it tends to get wet and stay wet. So these things rot from the inside. The broken welds that you see from the outside are the byproduct of this rot.

[09GLH]

Hate to resurrect an old thread. THis just happened to my 09 HB. I bought a brand new rear axle beam from Stoystown Auto Wreckers. They had it bubble wrapped in a box with all new hardware (bolts). They're about 3 minutes from the Flight 93 Memorial in Pennsylvania, for reference.

Absolutely gorgeous part. Only $600 compared to the $1200+ Toyota wants for new OEM. Worth looking up if you're in the mid-Atlantic area. I searched car-part.com for a junkyard part but couldn't find any.

#4211052332

https://www.stoystownauto.com/

https://wsimgproky.car-part.com/2690/2024/QTP/2690_1525690_01_web.jpg

[Billiam]

3+ years later our Yaris is going strong on the Scion xD axle. $600 is what I paid for mine back in April '22. That included shipping from 300 miles away.

[Thebailliekid]

Was the axle beam you replaced have the abs sensors? I was looking for a replacement for mine and I was told since mine had rear abs sensors I could use a rear beam from a yaris that didn’t have sensors. Does that make any sense?

[WeeYari]

The ABS sensors are in the hubs, not the axle beam.

[Billiam]

This thread revival got me thinking. April made 3 years since I installed the used xD axle. I decided to check things a little closer. The outside looks perfect. But that does not tell the real story. As I have mentioned a few times, it's the inside that's the real story. That's where the rot develops. By the time it makes it way to the outside, it's too late. Corrosion has eaten it's way completely through the welds. So I decided to use my borescope and peak inside the trailing arms. I'm happy to report that all looks good. Flooding that area when the beam was out of the car with Liquid Wrench Rust Inhibitor has definitely helped.

[Billiam]

And I will add that availability has changed dramatically in the last 3 years. At that time there were zero new ones available. No dealership could guarantee when they would come in. One dealership told me at least 6-9 months...and that was a guess. Retail was $1200. There weren't really in aftermarket ones either. Luckily that has changed. Looks like OEM and aftermarkets are readily available.

And as reminder, the same axle is used in Prius C and Scion xD

[enviri]

you can also get a '12-18 yaris SE set up for rear disc brakes :P

[Billiam]

you can also get a '12-18 yaris SE set up for rear disc brakes :P

Maybe so. But it's a Yaris. Rear disc brakes seem unnecessary. And at the time it was hard enough to find any rear axle, much less trying to find a specific one from an SE.

[professorm]

Did you have to do alignment after replacing the rear cross member?