the rear end of my '95 Dodge Ram 3500 is shaking and jerking when I back up slowly. It also shakes a little when I drive forward slowly. It doesn't do that when I speed up. What could be the problem?

What is your question?

I have 310,000 miles on my truck and I've had very few problems with it. I had a similar problem a couple years ago and it cost me $2400 to have the rear end taken apart. Only one of the parts was bad, but the mechanic said it looked like someone had taken it apart and put it back together wrong. I had never had anyone work on the rear end, so I don't know how it got that way. This new shaking is much harsher. The other time the shake was barely perceptible and never occurred while I was driving forward. This shake feels like an axle problem. I'm not a mechanic so I'm not sure how an axle problem would feel.

What makes this problem better or worse?

It seems to be worse once the truck warms up. I don't feel much when I first start driving

How long has your 1995 Dodge Ram 3500 had this problem?

I first noticed a very small shake about 5 months ago