[spasticnapjerk]

I've got a knocking sound that seems to be coming from just ahead of the dashboard at the firewall, in the center.

I hear it when driving on rocky roads, in fact it started when I drove a lot of dirt roads on a recent trip through Honduras, Nicaragua and Costa Rica. It's a pretty loud knocking sound, but it doesn't really sound like metal on metal. At first I thought it would be a loose shock absorber, as it maybe sounds like it happens when the front tires go down, rather than up.

We checked the front suspension and steering parts:
Rebuilt the ball joints.
Rebuilt the center link.
Welded body panels in wheel wells and below the windshield, where the wipers are.
Checked the Bilstien shocks.

Then I thought that it may be something in the roof, because I can feel the knock when putting my hand at the top of the windshield, so we took the headliner out, and removed the fairing, basket, and the light rack. Still getting the knock.

Right now, we're checking the rear ends of the torsion bars.

Anyone have any other ideas? Maybe something in the dash, or at the windshield?

Drew
Honduras

 

[Shaffer]

Wow, you're pretty thorough... Only thing I can think of is my old 87 Monte carlo SS. Pcv hose would pop off once in a while and it would sound like a damn rod knock..

 

[Shaffer]

Oh, oh... Jack the truck up but from the lower control arm so the suspension is compressed. Then wiggle the shaft of the shock. I had a BMW E30 that would make a sound I had a hard time finding. It got so bad one day I drove it and my steering was off to the left.. Then I hit a bump and suddenly had to fight the wheel from the right... Never had experienced that before.

 

[spasticnapjerk]

We checked the driver's side motor mount, it's got over an inch of play.

 

[TJTJ]

I was just about to say to check the motor mounts....if one is shot, do them all.