Rear End Problems?

[Redcoupe864+3]

Symptoms: lots of what feels like some sort of driveline "snatch"--real herky-jerky bucking -- at low road speed and off-throttle in my '86 4+3. More noticeable in the higher gears, and most distressingly, accompanied by distinct clanking-clunking from the rear end.
The whole affair makes me feel like a manual-trans rookie, and I've been driving sticks for 35 years, folks. Is this a prelude to real problems, or perhaps emissions-related, as I've heard from some quarters? Anyone else have the same symptoms? Thanks!

 

[Ken]

I don't know, but it sounds to me like you're simply dragging the engine rpms down too low, and your "lugging" it. How's it sound in the lower gears at the same speed/rpm? :confused

 

[Redcoupe864+3]

Well, as you might expect, it's less pronounced in the lower gears. Being more or less an adult, I'm not inclined toward light-'em-up driving, and therefore tend toward running as high a gear as conditions will tolerate. Which isn't to say I don't enjoy taking full advantage of the L98's bountiful torque, mind you. It's just that the effects of what may indeed be plain ol' lugging seem to manifest themselves more profoundly than I remember from the old days (60's). And the clank-clunk from out back is what really concerns me. Makes me wonder about U-joints, etc. Thanks, Ken.