What is this? I've been hearing this rattle sound when I slow down and stop (the car is too noisy otherwise) and it seems to be speed related cause it slows down too. It's coming from the passenger rear. I think it could be a shock that came loose or maybe something with the brakes (they're drum.) When I push down on the back end it does not bounce at all. The alignment is straight as ever. The brakes still stop the car. How can I tell what it is? It's just a little thing but any advice is welcome.

What does the rattle sound like? If it's metallic, check near the catalytic converters (under the passenger side).

When the cats break down, the stuff inside bounces around and makes a metallic rattle.

No, it's not the cats. I just had them replaced to pass smog, and anyway it was making the sound before that. It's non metallic. I think it's coming from one of the wheels. How can I check the shocks or brakes? I mean, can I tell by looking at them if they are broken?

I hear that noise every so often, and located it to the heat shield above the muffler/below the gas tank being loose, and it rattles with the vibrations of the car, especially when braking. If that helps any...

The muffler baffles or maybe even the washers on the exhaust hang straps. Take the whole exhaust and give it a shake.

Well, ok. I was hoping it was something else, but there really isn't anything happening but the sound. I'll check it in the morning.

Do your wheels have any unusual trim rings or center caps?

Jack up the car, put jack stands under the axle. Start engine and drop it into 1st gear. Go to passenger side, and listen for little bitty rattle noise! BE SURE to step on brake before puting it back in park. You'll probably forget anyway so a high speed grinding noise will be your first clue that you forgot! It might be helpful to have a helper to sit in the car and run the brake and gas for you.
In this case, when he forgets to apply the brake before trying to put it in park, you can blame him for the high speed grinding noise! How cool is that?

in a auto, there is no grinding noise.... if you jam it into park while moving, a tiny lil pin gets shoved in there and locks everything up..


so he will either screw the tranny, or he'll just have the wheels instantly stop.

Yeah, If you can get it passed reverse! Cmon man, I'm trying to add some humor here!! Gimmie a break!!

Well that's all very interesting.

Not to go too far off topic, but.......

Well if the wheels are turning fast enough it will make a grinding noise of sorts.... THe TH700R4 has a lever activated "chunk" (called a pawl - parking pawl) of metal that engages the outer part of the reaction internal gear support that is splined to the output shaft and has large "teeth" on it for the pawl to engage. It will skip across those teeth until it slows down enough to pop into one of the recesses between the teeth. Then it all stops turning . The reason it doesn't pop right in instantly is that the actuator rod for the parking pawl is spring loaded just for instances like this to protect things from blowing themselves to pieces .

As for the rattle, I agree with checking for exhaust/heat shield rattles...

Another heat shield location is around the sparkplugs. My shield on one side had been loose for a while and I could have sworn the engine was making the noise itself. They looked fine until I went to change plugs and noticed one wasn't attached to directly to anyhting, but wraps around something and I can't get it off

EDIT: just realized that the shields I'm talking about are exhaust shield and have already been mentioned

So Matt, Does this mean that there is a grinding noise when you try to put it in park with the wheels still turning and jacked up off the ground before stepping on the brakes?