quick "funny noise" question

[simon84]

Wondering if anyone can quickly suggest what this sound may be...

When I'm driving along around town, I can hear what sort of sounds like the trans or driveshaft is a bit like a can of bolts rolling around and rattling. More accurately, I'd say it's like a plastic pop bottle full of bolts because it's not a tinny sound. I'm suspecting driveshaft U-joint, but don't really have any experience with that to say it with any confidence. I have replaced the bearing in the middle of the driveshaft. I think it's called the carrier bearing. I did have a loud knocking sound when I replaced the exhaust and that was the drive shaft hitting the exhaust pipe where it crosses under the driveshaft. I managed to adjust that but it's possible that it's just nicking it as the engine vibrates but then I think I would hear it at idle too.
I have done lots of front end work so not likely any ball joints or bushings but of course, it's possible I'm missing something there...

It's not a loud sound at all so I'm not really freaking out or expecting anything to fail. I'm just hoping I can solve it and, if possible, be proactive about fixing it before it gets worse. I do have a spare driveshaft so I suppose I could swap that in and see if there's a difference.

I'm also curious if this is a common noise with tercels.

Hit me up with suggestions and I will report back if I can conclude what it is.

[dlb]

Hey homie. Is the rattling constant while the car is moving? I might sound paranoid but have you checked the gear oil level lately? Any issues with the CV axles? I've never encountered something like that before but those are the first things I think of.

[Paul]

I would consider safely supporting it with 4 jackstands and having an assistant idle it in first gear. You might locate the noise without getting under the wagon. Hopefully it's something simple, like a brake spring rolling around in the drum.

[Nordical25]

Is the sound coming always when you drive? Or only when clutch is pressed etc.?

[Petros]

checking the drive shaft u-joints is easy.

With the car on jack stands in the rear, parking brake off and trans in neutral, crawl under it to reach the rear end of the driveshaft. with hold the driveshaft on either side of the u-joint and rotate each side by hand in opposite directions. go back and fourth, if there is any movent at the u-joint, it needs to be replaced. usually it is the rear one that fails first. it has the most angle on it, and wears out the fastest.

the FSM tells you to replace the whole drive shaft assembly, but you can not buy new ones, so you have to press out the bad u-joint and install a new one. there is a procedure i wrote up in the repair guides on how to do that with hand tools, and get the new one securely pressed into place.

I do not know what else would make a noise like that, perhaps a bad engine mount. on the hwy in front wheel drive the rear driveshaft is not loaded, and just rotates with the back wheels, so it might make a rattling noise when in 2wd. you might try on a roadway, while driving in a straight line, put it into 4wd, and accelerate/decelerate, to see if the noise changes. if so, it likely the u-joints since it would be loaded differently and make a different sound.

good luck.