tin cans in the back

[palaxdad]

I started getting banging tin can sounds coming from the rear end 2 days ago.

It is more noticable when there is torque on the rear wheels like under acceleration or decelaration.

It is hardly noticable when cruising (maintaining speed) at any speed.

Sometimes it dissappears for 10-15 minutes, and then magically it reappears.

This happened for 2-3 days last spring and then totally dissappeared until this week.

I suspect a half shaft but wondered if anyone else has experienced this.

[adrian jaye]

torque tube ???

have you checked and replaced the tranny oil ?

[SoCal Driver]

CAT breaking up? Loose heat shield? Old beer cans?

CV joints can make a clattering sound under load.

[..P]

A cat breaking up can most certainly sound like a tin can banging around, even with the car sitting still and just revving up through the harmonic band to cause the rattle.

P

[palaxdad]

I suspect drive train problem, probably not tranny because the frequency of the thump is changed with speed. Thumps get faster as the car accelerates, slows down as I decelerate. Changing gears doesn't affect frequency.

I checked for beer cans. Found 2 bottles, but no cans...

[Dark Skies]

Does it sound like it's coming from the wheel end or nearer to the centre? Manual or auto trans? Thump as in dull? Does it come with a rough once per wheel revolution type clacking sensation - like a stone caught in the tyre tread?

[palaxdad]

It sounds like heavy metal hitting heavy metal - but muffled, not metallic. It's hard to pinpoint the sound while driving, but it sounds like its to the right of the transaxle. It is a manual and the transaxle was replaced about 20k ago. The sound is definitely related to the speed of the axle/tire, not the transmission, but it sounds like it's slower by maybe 1 to 4 than the actual speed of the car.

[Dark Skies]

I'd jack up the offending side of the car, remove the wheel and see if I could feel any roughness in the area of the rotor - if there's a distinct catching sensation every revolution it might be a problem I've recently experienced - a worn stub axle causing float under the outer wheel bearing resulting in a cracked race.

Or it could be either worn CV bearings or hopefully, as with a lot of older cars, the grease having hardened and simply requiring repacking. Grab hold of the shaft and see if you can feel a lot of up and down movement - it's supposed to have some end float so don't confuse the two.

[palaxdad]

I wondered about the grease packing as it started when it was less than 10 degrees out. But, the last time this happened it was early summer.

[Z-man]

Do you have any backlash in the drivetrain? If you let off the gas while the car is in gear, do you hear a clanking sound?

If so, it's most likely a drivetrain / tranny issue.

-Z-man.

[SoCal Driver]

Wheel bearings. Cracked race. Most likely the inner race to the roller bearing. This is the outside bearing on the stub axle. The inner bearing is a ball bearing. Takes up the lateral loads. The outer roller bearing takes up the vertical load.

CV's can clunk too. Find an empty parking lot, roll down both windows and make tight right and left turns. You will hear more noise one way than the other.

[palaxdad]

just replaced the right halfshaft. that did it. thanks for everyone's feedback.

[SoCal Driver]

Save your money. Most likely you will have to do the left one in a few months.

[palaxdad]

drivers side was done when new transaxle was replaced last February. This one is supposedly rebuilt with Lobro parts so it should hold up. Other one was a rebuild and it's been fine so far...