620 drive train clunking

[Eric Garside]

Bought a new 78 k/c and its making a clunking in the drivetrain when I take off and up shift. I thought it was a u-joint or shock bushing but I crawled under it today and could find any loose or worn out components. Any ideas on where to look would be much appreciated. And I know how we all love pics ENJOY!!!

[Zeusimo]

The Truck Looks Lowered So Check Your Driveshaft Angles If Their Off That Causes Vibration

[yello620]

Lowered without a carrier bearing spacer and a worn out carrier bearing mount bushing. :D

[Eric Garside]

It goes 70 with no vibrations and the bushing looks in really good shape, I dont recall if I saw a spacer but the angles looked good. Id imagine some mean vibrations at highway speeds if it was related to driveline angles or the carrier bushing.

[datzenmike]

Loose motor or tranny mount bolt. Loose driveshaft bolt. Exhaust pip hitting something. Spare tire carrier hitting something. Most likely the rubber isolator around the carrier bearing though.

[Z-train]

Is that a Sun tach?

[datzenmike]

Does look like one eh? I had one, a Sun Super tach back in 1970.

[Eric Garside]

It's not fully functional what ever it is. I'll get a better pic after work

[datzenmike]

It goes 70 with no vibrations and the bushing looks in really good shape, I dont recall if I saw a spacer but the angles looked good. Id imagine some mean vibrations at highway speeds if it was related to driveline angles or the carrier bushing.

 

 

Grab th driveshaft and push it side to side, up and down. It should be firmly held by the rubber isolator but will flex slightly. The motot and tranny mounts you can check bty prying upward with a 2x4 to see it it lifts off.