Prius Prime Suspension Wearing Out Quickly

why were they replaced? Shop recommendation or abnormal tire wear? If your struts are bad there should be abnormal tire wear (cupping, inside or outside tire wear) and you'd likely need a new set of tires to go with the strut replacement. Most suspension and wheel bearing issues happen on the right side of the car, from parallel parking, rubbing against the curb - placing inward pressure against the tire and curb , and jumping the curb.
I believe most of us has good luck with OEM struts, though you may be an unlucky outlier.

 

138,000 km is about 85,000 miles.
Post 2 asks great questions.

FWIW
In other street cars I notice suspension improvement when replacing shocks at 50K miles.
I've read on Mazda Miata MX5 forums some feel shock degradation at 20K miles.
With "racing shocks" monthly nitrogen recharges/ checks are prudent and oil changes at 5K miles always improve the suspension feel.
Again, for what it's worth.

 

Yeah, second this. You "might" be the the dealership's cash cow.

How are you with speed-bumps, say between slow-to-a-crawl and take-them-at-posted-speed-limit?

 

it sounds like something defective in the rest of the car is causing this. maybe have a good suspension shop look everything over.
i haven't read of many others having early problems, if any.
at least you got 100k out of the second rears and 140k out of the front.
maybe the first rear replacements were defective.

 

Here appears to be the problem. The car is not designed for off road driving with heavy loads. The weight limit is posted on the door jamb. Post #1 says:


I travel on pavement about 90% of the time, with 5% on graded gravel roads, and 5% on not very good gravel roads. I have used my car about 20-25 times for transporting 400-600lbs of materials from home depot, but otherwise the car is empty. That load, when added to the 200 LB driver and another 200 lb for the passenger is enough to destroy the shocks when driven on poorly paved roads.

I would suggest that there is no problem with the Prius Prime if loaded as it was designed to be driven.

 

I'm not even going to try an guess what or why the shocks needed to be replaced. Trying to second guess what a service dept., repair shop or owner wants done to a car is a game without a winner. If shocks are the only issue you've had with your 2018 Prius so far, I think that is pretty darned good.
Just for giggles add the 300 lbs / 136 kilos to your 400 lbs of Home Depot materials. They do sell heavy duty suspension parts for these cars. Take a look around this general Prius forum and you'll see how many others have already added suspension enhancements.

 

Does the Prime already have heavy duty rear suspension components? Since it is night day difference you did wear out the parts. I’ve never replaced any shocks on a Toyota but I have some new ones in a box for my truck somewhere. Good to stick with factory parts.

 

That's a good question. I tend to pay attention to the limitations when they are posted on the door jamb and (I think) within the user's manual. I assume that the last part is true since I saw it somewhere BEFORE I found the limits listed on the door frame.

You did not specify in the original post whether the 800 pound load was carried on the badly paved gravel roads that make up 10 percent of your normal driving. As a result of the fore-warning, I'd expect a shorter than normal life from the shocks of a car configured as a sport car that is being used as a pack mule (complete with gravel roads and overload).

 

I appreciate your bringing this to the attention of the Prius Chat members. At some point in the near future I'll be picking up some landscaping river rock in 0.5 cu ft bags. I did that successfully in my 2017 Prius Prime, but I was not watching the weight closely when I put a few bags per trip in the hatch.

I suspect that I was saved by my poor calculations that resulted in multiple trips back to the store for "yet another couple of bags".