Rear shock wear vs. Front Strut Wear

[The Critic]

My Prius has a macpherson strut suspension in the front and a torsion beam suspension in the rear. In the rear, the springs sit parallel to the shock absorbers, as they are separate units. On this type of design, is it possible for the rear shocks to wear out before the front struts?

In the last few thousand miles, I have noticed that the ride in the rear of the car is rather rough compared to new. For instance, you can feel the roughness and choppiness from the driver seat. The rear end also does not seem to rebound nearly as well as the front. The front struts though, clearly, are working just fine.

At first I tried rotating and rebalancing the tires; the improvement was minimal. At the time I had springs from TRD on the car, so I reinstalled the original Toyota springs from the factory. The rough, choppy ride from the rear now became less noticeable, but is still there. I currently have 43,000 miles.

A new set of rear shocks from Toyota is $85 and requires minimal work. I think I may try this next.

Thoughts?

 

[Shannow]

Dunno, what's your Dad been carrying in his car ?

 

[SteveSRT8]

It may be hard to tell without first removing a shock to actually feel its dampening ability by hand.

Many times the shock simply wears its own bushings to the point of slackness, some notice it, some do not.

Is there any cradle in the rear of a Prius? I'm not familiar with the underside of that vehicle, but most FWD use the most ridiculously cheap rear suspensions out there.

 

[chrome]

Only $85 for a set of OEM rear shocks? Worth a try, plus you have an excuse to use your IR cordless impact!

 

[Doog]

My Rav4 is exactly the same. Front struts perfect and rear Tokicos going mushy and on just getting some oil dampness. I found the OE shocks on line for $62.

 

[HerrStig]

If you keep a car long term, one set of really good shocks like KONI or Bilstein is probably a better investment than two sets of cheap ones.

 

[The_Jeff]

What's the weight distribution of a prius? I expect a little more weight in the rear due to the battery pack and what not compared to a corolla. More weight means more work; naturally you'd expect it to be designed in/for but maybe not.

The valving in your stock shocks was designed (naturally) for stock springs, the more sudden reversal of direction from (stiffer) lowering springs might abuse it somehow. Not a shock expert, just throwing it out there.

 

[fdcg27]

You might also consider a set of higher quality aftermarket shocks.
43K doesn't sound like very long life, although I don't know how good or bad the roads you use are.
In your part of the country, I would expect pretty smooth roads, but given the budget problems of your state, maybe not.

 

[SatinSilver]

The TRD springs likely cooked your rear shocks. The shortened springs put an increased load on the shocks. Plus TRD doesn't even make lowering springs for the Prius.

 

[OVERKILL]

Originally Posted By: Shannow
Dunno, what's your Dad been carrying in his car ?


Ouch!!

 

[mechtech2]

Of course it's possible that the rears can wear out faster than the fronts.
Or, the exact opposite!

Get good replacements, spend a bit more. Internet homework first!

 

[The Critic]

Originally Posted By: HerrStig
If you keep a car long term, one set of really good shocks like KONI or Bilstein is probably a better investment than two sets of cheap ones.


Unfortunately, OE is all that's available. But I am OK with the price and their service life.

Originally Posted By: eljefino
What's the weight distribution of a prius? I expect a little more weight in the rear due to the battery pack and what not compared to a corolla. More weight means more work; naturally you'd expect it to be designed in/for but maybe not.

The valving in your stock shocks was designed (naturally) for stock springs, the more sudden reversal of direction from (stiffer) lowering springs might abuse it somehow. Not a shock expert, just throwing it out there.


The weight distribution is 60% front, 40% rear, yes quite a shocker.

Your thought about the TRD springs being responsible did cross my mind, but as I will mention below, the PLUS package cars that use these springs do not have different dampers.

Originally Posted By: satinsilver
The TRD springs likely cooked your rear shocks. The shortened springs put an increased load on the shocks. Plus TRD doesn't even make lowering springs for the Prius.

TRD makes them for Toyota; the springs were part of the new Prius PLUS package:

http://www.ebay.com/itm/2010-2011-2012-T...0-/280960062902

Updated dampeners were not available. There was nothing to suggest that the Prius PLUS package vehicles had different dampers available.

 

[martinq]

Originally Posted By: The Critic
Updated dampeners were not available. There was nothing to suggest that the Prius PLUS package vehicles had different dampers available.

Are the dampers a different part # from the Corolla or similar?

+1 on the Koni / Bilstein suggestion.

 

[PandaBear]

IMO, your "performance" spring killed the shocks and if you had stick with the original rear spring it would last longer.

I've had my rear worn out before the front in the past, but I was carpooling with 3-4 people all the time going 90mph, at around 150k miles when replaced.

Most aftermarket OEM replacement shocks (i.e. KYB GR2, Tokico Blue) warn that warranty would void if you lower the car. I was surprised that Toyota said use the same shock when using high performance spring.

 

[The Critic]

Update: ordered new rear shocks from the dealer. $32/ea delivered.

I will try those first. If this does not restore the suspension to like-new condition, I will proceed to replace the fronts as well.

 

[hattaresguy]

Wow Toyota must use cheap shocks. They should last at least 100k miles unless your bouncing around NYC or some other major city with pot holes a mile deep.

 

[JHZR2]

My father's corolla went through rear shocks at around 50k.

The previa lost a shock when the shaft went bad at about 180k. They still worked fine, just had a dragging shaft.

 

[hypervish]

My RX300 still has original struts on the front at 190k miles. I replaced the rear struts at 170k miles even though they didn't need replacing, it was only the strut mount in the rear that was making noise.

 

[zzyzzx]

My own personal experience on a rather limited number of cars suggests that rear ones tend to wear out faster, and I have no idea why,

 

[SteveSRT8]

I have found that shock quality varies wildly from brand to brand.

My Chrysler has Bilstein front and Sachs Nivomat rears. They are practically permanent!

Our fleet trucks used to wear them out in less than 50k miles, but with the latest generation G vans they went to a very nice gas charged model that lasts an honest 100k miles. Even then it's usually the bushing that is shot, not the shock.