Rear Suspension Noise On Bumps

[PhilKC]

When I go over bumps in my 67 Coronet, the rear suspension makes a crashing sound. To my knowledge, nothing is loose but it's done it since I bought it in 1999 and it's annoying.
Are the leaf springs slapping each other? How do I fix it or at least make it less noisy?

 

[Sam69sat]

First thought for me is leaf spring bushings.

Something like these.

1967 DODGE CORONET Moog Chassis Parts K7308 Moog Leaf Spring Bushings | Summit Racing

Free Shipping - Moog Leaf Spring Bushings with qualifying orders of $109. Shop Leaf Spring Bushings at Summit Racing.

www.summitracing.com

 

[pnora]

Make sure the upper shocks are tight and the bushings are good. That is the most common area for noises.

 

[Chargerkiddave]

And make sure the rear shocks are long enough.

 

[71RRHI]

You had the car since 1999. I would change the shocks and all the bushings, they atleast 26 years old.

 

[Don Frelier]

The other culprit can be the tailpipes.
They need to be oriented correctly and be centered over the axle.

 

[WileERobby]

I'm assuming inside the trunk is empty, or all is tight/intact.

 

[Cranky]

If you have 'junk in your trunk' then it can sound that way.....

 

[DeltaV]

Check the mountings of the gas tank while you're doing the shocks and checking/replacing bushings on leaf mounts/shackles.

Old cars. Gotta love them.

 

[68 Sport Satellite]

Is it a crashing sound or more of a bang or bam? Haha it's tough to describe sounds sometimes. I had a hard bam sound happen every time driving over a bump when I installed an adjustable pinion snubber spaced only 1 inch off the floor pan. The stock snubbers have much more clearance. I removed that sucker right away it was so annoying.

 

[PhilKC]

Thanks for all the great suggestions. I'll check the bushings as well as if the exhaust is hitting anything.
The trunk is completely empty.
The sound is like when a steel trailer goes over a bump. It isn't a dull sound, it's sharper like metal hitting metal.

 

[Cranky]

Don't think anyone mentioned the upper shock mount being broken or came loose from it's welded in position.....?