Quote Originally Posted by v8nutz View Post
Have you ever seen the big counter balance weight that bolts to the tail shaft on some cars? I think it was the factory's way of dealing with a vibration they couldn't fix. Maybe you could get one from a wrecking yard and bolt on there.
Quote Originally Posted by 34_40 View Post
Yes, to modify a harmonic issue.I've seen a couple snapped off right next to the bolts. Most hot rodders toss'em away.
Yep, that's what they're for. A lot of the ford diesels had them stock. I've seen so many riding on the tube making noise because they've been flung off. The drive line shop I use never puts them back on and I've never heard any complaints. Maybe the factories tolerances were off and they was their fix to get those vehicles through the warranty period?