Creaking sound from rear suspension on 06

[Patrick Wong]

Originally Posted by Sarge

...The car currently has 97K KM on it, I had the brakes cleaned once by the dealer in January at 72K. The noise started before that, but has become more pronounced in recent months.

I do have a jack and will try lifting the car up as suggested, and will report back on the results...

Hi Kevin,

When you spin each rear wheel after the car is raised, if you hear noise then it is probably either a wheel bearing or brake noise.

If you want to inspect the rear brakes, then remove the tire, release the parking brake, and then you can pull off the drum with your hands. If the drum is stuck, then buy a couple of 6 mm bolts from your hardware store, 25 mm or longer. Insert them into the two threaded holes on the drum, and rotate clockwise. This will force the drum off the hub.

If you want to clean the rear brakes, buy a can of brake parts cleaner and spray the drum interior and the drum shoes liberally. Spray off the brake wheel cylinder as well. If you see brake fluid leaking this is bad and the wheel cylinder will need to be replaced or repaired. Catch the cleaner runoff with old newspaper.

[Manksgloob]

I hear creaks in my 2006 after I set the parking brake, too.

As an aside, is the parking brake *supposed* to be able to hold the car in place, even when in gear? (Or rather, is creep is not supposed to overcome the parking brake?)
How about in reverse?

[Patrick Wong]

Originally Posted by Manksgloob

...As an aside, is the parking brake *supposed* to be able to hold the car in place, even when in gear? (Or rather, is creep is not supposed to overcome the parking brake?)
How about in reverse?

Yes. The parking brake is also an emergency brake, and is supposed to help you stop the car if the regular service brakes fail. If the parking brakes cannot overcome "creep", then they certainly won't help you stop the car when you are traveling at speed; or say if you are parking on a San Francisco hill...

You need to depress the parking brake pedal reasonably hard. If after doing so, you find that the parking brakes are ineffective, then the rear brakes need to be adjusted. The adjustment is of traditional design, a toothed wheel inside each rear wheel brake assembly allows more or less clearance between the brake shoes and the brake drum.

[Sarge]

Originally Posted by edthefox5

Your very welcome. Noises in my car drive me nuts too. Post on results.

Hi Ed,

I finally got around to pulling my jack out and investigating, and using your recommended tests, I have proved that it is conclusively the suspension, and not the rear drums.

Using a piece of wood and a brick to activate the suspension, that is DEFINITELY the sound. Does not take much effort to reproduce. In fact, I took out my camera and recorded a video so you can see exactly what I mean. Unfortunately, my 8MP camera made a huge 52MB file, but anyone interested can see it here;

Download link.

I do apologize for the banner ads on that transfer site and the large file size, I don't have the time right now to find some software to downsample it.

Now, it *sounds* like it is coming from the strut itself, though it is difficult to be sure. Curiously, both sides do the exact same thing.

In terms of performance, the rear suspension seems to perform fine, I don't get any inordinary bounce or riding low. It is just this noise that drives me batty, especially when cruising "silently" on electric.

BTW, I am at 98K KM, and I have been listening to this since sound since ~ 50K KM, which was before warranty expired. Had the dealer check it out twice during visits prior to warranty expiring, but they must be hard of hearing as the claimed they could never hear anything. In other words, no warranty, unless I try to push the issue that I reported this some 40K KM (~1 year) ago.

Thoughts or advice on where to go from here?

Thanks...

[Patrick Wong]

Originally Posted by Sarge

...Now, it *sounds* like it is coming from the strut itself, though it is difficult to be sure. Curiously, both sides do the exact same thing...

BTW, I am at 98K KM, and I have been listening to this since sound since ~ 50K KM, which was before warranty expired...

Hi Kevin,

If this sound bugs you, then it seems reasonable to have the rear shocks replaced.

Regarding a warranty claim, unless the shocks were leaking substantial fluid prior to warranty expiration, it would not be reasonable to expect the dealer to effect a warranty repair (since the dealer staff did not hear the noise that you noted).

[edthefox5]

Good you have found it. Thats half the battle. First look real carefully for a leaking shock. If OK Then Try spraying some Liquid Wrench lube on all the mounting area's. Don't go crazy just lube all the attachment area's.I think those are coil over back there. Lube the coil attachment area also.
If no joy its shock time. I like Tokico and KYB. Both are superior to stock Toyota shocks. Its probably time for struts up front too. Any reputable shop can install them. I'd buy high quality after market stuff and have a shop put them in. Its no big deal. Nothing special to a Prius. But with higher quality struts up front the car will feel much better. More tight. Struts up front require front end alignment though. Parts all around are about $ 700 plus I'd get the rotating plate that mounts on top of the struts I forget what its called but it has a bearing in it. Buy those 2 from the dealer. Labor is about $ 400 so maybe $1100 all done. But the dealer will kill you on all around shock replacement.Good luck.

Patrick: Not sure if shocks are even covered under warranty. There a wear item yes?

[Patrick Wong]

Originally Posted by edthefox5

Patrick: Not sure if shocks are even covered under warranty. There a wear item yes?

Hi Ed,

I believe that the shocks/struts are covered under the 3 year/36K mile warranty. They also seem to be covered by the Toyota extended warranty since they are not in the excluded items list, according to posters who researched this.

[Sarge]

Hi guys,

Sorry for not responding to your last messages, I did not have this thread subscribed and did not think to check back.

So, the latest update on my squeak is that it is getting worse, to the point neighbors have pointed it out to me when I drive by.

I did some more googling on the matter, and I found a message from a Camry driver on another board and someone suggested they had a similar problem that was solved by replacing bad strut gaskets - do you guys think that may apply to the Prius as well? Seems reasonable...

Secondly, I had a *very* interesting conversation with my father-in-law who is in town this weekend. After riding in my Prius, he commented about the squeaking, and how his Tercel made a similar sound back when it was brand new (1998). As it turned out, the dealer said it was "bad shocks" and replaced them under warranty; he was told that the rust proofing *by Toyota* had gotten into the "shock" (strut?) and somehow damaged it to cause it to make noise. (He has since had two new Corollas and foregone the rustproofing, with no problems).

The reason I find this very interesting, is I had the same (overpriced) rustproofing by Toyota when I got my car... Now what I am wondering is whether there is any realistic correlation here...

Of those who have experienced a similar squeak, did you have Toyota rustproofing done on your car?

Both rear shocks exhibit the same noise depicted in my video above, so it is not a case of a simple "defective" shock. So far as I can remember, symptoms have been there since new, though *much* more subtle at the beginning, and I just brushed it off as being neurotic (when have you ever driven a car without an ICE running? ), particularly when the dealer repeatedly told me "no noise heard" (to which my gut response was "are you deaf??") - though my reporting the noise was documented on the work orders each time. Now, whether on electric or ICE, you can hear it while rolling, as long as you have a window open.

(I wonder if it is possible that some chemical in their rustproofing solution is damaging to the plastic/rubber/whatever material of the gasket (where it should not have been sprayed), causing it in turn to break down? Just a totally uneducated guess on my part...)

Anyway, now the car makes a nice long creak each time you sit in it now (or sometimes even just closing a door), so there is no way they can deny hearing it. I plan to go to the dealer later this week to see what they say about it. If there is any chance the (poorly-applied?) rustproofing could be held liable, you better believe I am going to try to get Toyota to cover some or all of this!

Thoughts?

Sorry for the rant/long post...

[galaxee]

there are lots of noises that can come from the suspension... you name it, it probably causes a noise if something's wrong. you need someone who really knows their suspension sounds, i bet the right person can pick that out with a sufficient test drive. of course, finding that person is the hard part!

every car that passes through the southeast toyota port gets this undercoating spray stuff, and DH didn't encounter many bad struts in his time at the shop. we're nearing 60k with no abnormal noise with the undercoating.

honestly, if i were you i'd be looking for someone who knows their suspension whether they were at the dealership or elsewhere. clearly something's wrong, and the dealer is happy to pretend all is well and send you along like nothing's going on.

[Sarge]

Thanks for the reply, Galaxee.

I plan to start with going back to the dealer one last time (suggesting to check this strut gasket I heard about), and if they come up empty I will find another shop to look at it. I really hope this doesn't come down to replacing the entire rear suspension, as that seems excessive for an irritating noise when they still operate fine.....

Kevin