Problem with tranny or rear end?

[67belv1]

Took my 67 Belvedere for a quick drive and all the sudden I got a noise that sounded like something dragging under the car. It’s a 727 auto with a 8 3/4 rear. Coasted in to driveway and thought maybe U joints but not the case. No fluids running out anywhere. When coasting with car in drive it was making the noise, put it in neutral and would stop. Thinking transmission but what should I look for to narrow down the problem. Tail shaft of tranny has some slip up and down when push on it but not sure if that’s normal. Need some direction

 

[Cranky]

Check your converter bolts. Take the lower shield off that's on the bottom front of the trans and see if the bolts have been rubbing on it.....heck, start it up once the shield is off and see if the noise goes away.

 

[davek]

have you done anything to the car lately?does it make the noise backing up? Try what Cranky said easy quick look and go from there.

 

[tak419]

If it stops when the car isn't moving I highly doubt it's the converter bolts, those will make noise as soon as the engine turns. It could be something in the brake system dragging. Might be a good idea to move forward and back in a driveway and have a friend help listen. Last resort put on jack stands on put in hear and get out and listen where the noise comes from but DON'T get under the car when it's running.

 

[Fran Blacker]

Trans rubber mount?

 

[Cranky]

If it stops when the car isn't moving I highly doubt it's the converter bolts, those will make noise as soon as the engine turns. It could be something in the brake system dragging. Might be a good idea to move forward and back in a driveway and have a friend help listen. Last resort put on jack stands on put in hear and get out and listen where the noise comes from but DON'T get under the car when it's running.

Had one that did exactly what the OP mentioned. Put it in neutral, the rattle would stop, put it in gear and it's back. It baffled me for a bit until I listened for where the noise was coming from and that meant getting under the car and listening. When there's no load on the converter, it's positioned in one spot and when it's under load, it's going to usually move forward a hair. Might be just the PSI difference in the fluid, I don't know but once I 'adjusted' the shield, it quit making the noise....and I also had a loose bolt. Yes I got under the car while running. The front end was up on ramps and the rear was on stands and with the parking brake on so the drivetrain couldn't turn.

 

[67belv1]

It’s not the converter bolts. They are good. Only does it in drive when moving. Not coasting in neutral either. Here’s a pic of the rubber tranny mount. Would that cause it like mentioned? It looks like it tore along the top and see splitting on bottom

 

[Fran Blacker]

It’s not the converter bolts. They are good. Only does it in drive when moving. Not coasting in neutral either. Here’s a pic of the rubber tranny mount. Would that cause it like mentioned? It looks like it tore along the top and see splitting on bottom

View attachment 808321

Finish it off, find a steep grade and back up it.

 

[67belv1]

Do you think that’s what’s causing it to make the noise?

 

[5.7 hemi]

That’s the way those look. Only to know for sure would be to take it out. They are cheap, so wouldn’t be much to replace it.

 

[Fran Blacker]

Do you think that’s what’s causing it to make the noise?

Usually in reverse it makes noise. In a safe place with some room, push hard brake with trans in reverse give it a LITTLE ( enough so it's straining against brakes) gas and let up on the GAS if you hear a clunk where rear trans mount is, think you found it.

 

[Cranky]

After rereading your posts.....what kind of noise are you hearing? 'Hearing a noise' can mean so many things.

 

[Fran Blacker]

He started a new thread? Noise from rear end.

 

[Cranky]

He started a new thread? Noise from rear end.

Does he go into more detail? lol