3 times now in the last week, 2 times today. I have gone over some bumps in the road the rearend of my truck starts to bounce violently. It kind of scared the crap out of me. The first time I thought something broke and pulled over but couldn't find anything missing or broke. Now it has happened 2times on my way to work. I do notice a little oil seepage out of the front of the rear differential.
All 3 times I was going between 45 and 55 mph, once was going over railroad tracks the other 2 times just your normal pot holes which I travel over 5 days a week!!!
The truck is a 96 2500, 4x4, extended cab long bed, I've had it just about a year, the guy I bought it from claims the tranny was rebuilt and differential serviced about 2 years ago now.
Would appreciate any ideas.
Thanks,
Tim

 

When were the rear shocks changed last?

They might still be the ones Dodge put on at the factory.

 

I noticed this on my truck after I did the front shocks only. Completely went away when I did the rears.

 

also check the rear end u bolts I couldn't find the problem I even had a few shops check I THOUGHT SOMETHING WITH REAR BRAKES and noone could help me then I was under there and seen the u-bolts were loose replaced them and one of the blocks between the rear end and the leaf springs and totally went away, the reason I guess the shops didn't know is because up on the lift the u-bolts would appear tight but on the ground and it was obvious. good luck

 

That might be the problem. I guy I bought it from told me the front shocks had been changed but I don't remember if he said the rears were new or not.
I've checked all the u bolts and universal joints and all look ok.
Is there a way to check the shocks? without taking them out? With the stiff rear springs it's kind of hard to bounce it and see if they are bad!!!
Anybody have any recomendations of the kind of shocks? and should I replace all 4 while I'm at it?
Thanks for the help.
Tim

 

After doing some further research here, I'm wondering if my problem is the so called 'death wobble'???
I thought the problem was coming from the rearend, but as you are bouncing around trying to keep control it is very possible that it may be the front end?!?!
Any ideas from anybody??
Thanks,
Tim

 

On my 03(which has badddddd dw,hopefully will be fixed next monday,it seems like the vibration is coming from the back when it hits a bump but doesen't go into full death wobble,so maybe you are onto something here.

 

those leafs are set up hard for heavy loads. Maybe your shocks are set with too much rebound damping so that the motion is transferred to the bed. Are these adjustable?
I put rancho 9000 rsx's on and I dont like the single adjuster much. Id much rather get a set of good shocks with compression and rebound next time Im in there.