Knocking sound from rear

[Vella's Alero]

So this has been happening for about 2 months now but now it is happening a lot more frequently. Whenever I go over a bump or sometimes even when I hit the brake a touch hard, I hear a knocking sound from the rear passenger side of the car. I haven't checked if it is the trunk, license plate, or strut/shock assembly so I have no clue what it could be.

Any ideas?

[Ttop191]

struts, no doubt

[AndyT3]

Yeah, its most likely an upper strut mount. Or something in that assembly at least. Common issue.

[Vella's Alero]

Would it hurt if I left it till summer like that or would it damage something else?

[Ttop191]

well, i drove mine with bad rear struts for like 3 months with no problem, but don't be hitting bumps too hard, you don't want your struts laying in your trunk do you?

[Kilroy]

Have you been forgetting to feed your Trunk Monkey?

[Daytona]

I've had that same issue for a few years now. If it's the USM then it got damaged 3 years ago when I bent my original rim on a highway pothole. Have had no alignment issues or unusual wear on the tire, but I guess I should get it checked out.

[AndyT3]

Well, my front and rear strut mounts have been making noise for quite some time and its been fine. If the ride is still decent, then don't worry too much about it, the mounts are just getting loose. When the ride starts to get worse, then I would seriously consider new struts.

[Vella's Alero]

Just an update here, it was my upper strut mounts and I am getting them replaced next Tuesday. I basically got my dad to drive the car while i laid in the trunk to hear exactly where the noise was coming from. Then a mech just confirmed. Thanks for the help guys.

[hotrodwolf]

So i know mine are bad because i can pull on the rear wheel and move it. Is there a way to just replace the mounts and has anyone done it? Is there certain replacements i should use IYO?

[Vella's Alero]

I just had the mounts themselves replaced and they work fine now with no noise. I am gonna have new struts and shocks put in over the summer but yes, you can replace just the mounts.
The ones that I got were the Monroe ones that were in stock at the auto shop.

[ccsmith87]

Originally Posted by hotrodwolf

So i know mine are bad because i can pull on the rear wheel and move it. Is there a way to just replace the mounts and has anyone done it? Is there certain replacements i should use IYO?

Yes, you can replace just the mounts. If you plan on doing it yourself you'll need some jack stands and a spring compressor. Along with some common tools of course.

I also recommend that you change your struts and springs (in pairs of course) because 8 times out of 10 they are worn out aswell.

NAPA Auto Parts sells a Monroe Quik-Strut assembly that is lifetime warranty and requires no spring compressor to install them. So even if your spring breaks and the rest of the assembly is fine you get everything under warranty. Really a great way to go. =)

[zzyzzx]

What did the beat up strut mount look like?

I've read in the Grand Am Fourm about being able to lube the upper strut mount and having the noise go away. I have some sort of noise coming from mine, but have no idea exactly where, but everything looks fine but I haven't jacked up the car yet. If it matters, mine has 27K miles, so anything made of rubber is naturally suspect.

[zzyzzx]

I'm specifically thinking of this thread which says to use lithium grease:

http://www.gaownersclub.com/forum/sh...ad.php?t=89113

[hotrodwolf]

I've used greases on other cars with lower mile with good effect. They are usually more of a squeak, but are still tight. It wont work on mine because i can literally watch the strut move over a half inch in its mount.

[zzyzzx]

Originally Posted by hotrodwolf

I've used greases on other cars with lower mile with good effect. They are usually more of a squeak, but are still tight.

Pretty much decribes my car.

Originally Posted by hotrodwolf

i can literally watch the strut move over a half inch in its mount.

[zzyzzx]

Originally Posted by ccsmith87

Yes, you can replace just the mounts. If you plan on doing it yourself you'll need some jack stands and a spring compressor. Along with some common tools of course.

I also recommend that you change your struts and springs (in pairs of course) because 8 times out of 10 they are worn out aswell.

NAPA Auto Parts sells a Monroe Quik-Strut assembly that is lifetime warranty and requires no spring compressor to install them. So even if your spring breaks and the rest of the assembly is fine you get everything under warranty. Really a great way to go. =)

First off, the spring compressor is a really cheap tool that you can get from Harbor Freight:

http://www.harborfreight.com/macpher...-set-3980.html



MacPherson Strut Spring Compressor Set
Item # 3980

Quickly and safely compress coil springs in order to repair or replace MacPherson struts, shock absorbers and spring sets.

Uses 15/16" hand tool or impact wrench
Includes two safety hook sets
Comes with two legs for balanced compression

Only: $14.99 Sale: $9.99



And replacing struts is easy. I've never replaced the strut mount, but it's only a few more bolts once you have the strut assembly removed. You'll also need a breaker bar. Struts are only intimidating if you have never replaced one before, but once you are done you are an expert. It's really not much harder than replacing the alternator on this car (I.E. - easy).

[ccsmith87]

That's about the cheapest spring compressor I've ever seen... is it safe?

[hotrodwolf]

I just looked into parts and the monroe quick strut is great. The upper mount alone is $46 plus compressor. The quick strut gives you everything including mounts, strut, spring, for $125! No compressor needed.