Crazy knocking on hard acceleration

What parts are they using to rebuild it? Cheap parts (Moog) fail a lot faster than good ones. Spicer or OEM for the joints and carrier bearing. But at this point, if that one has been rebuilt so much, it might be better to start over with an unmutilated shaft and get that serviced with OEM parts. Try car-part and see what you can find.

The other option would be a "new" drive shaft. There is some company out there making 'em (DuraShaft), and then rebranded and sold by all the usual suspects, dorman, drive shaft pro / drive shaft store, etc... However, the tube on the shaft is smaller diameter than the OEM ones, and given your track record might not be suitable.

 

I cant believe everyone cant see the excessive axle wrap...

These trucks are sold with a softer suspension, So the leafs are flat at best, and actually sunken in a little on RWD's.

At full torque your putting that whole drive line in an unnatural position....

Your slip joints must be nearing their limits....

Thats slowly destroying everything........ the UJ's, the carrier, trans mount, rear trans seals, front different seal, all getting squeezed back and forth...

Thats putting a ton of stress pushing the whole tranny and motor forward.....
thats amazing to watch.....thankyou...

motor mounts are probably suffering too..
the mounts are actually what's pushing the truck down the road...
at least until the axle catches up with the truck.


damn good thing you stuck that camera under there....
those U bolts much be on there pretty darn tight...


These are cowboy caddy's.......made and sold only for americans.....
el gringomobile....

 

I just noticed the tail pipe.....it moves back and forth so much....
from the engine rocking back and forth...

the rigid hanger holding the muffler is gone and replaced with two straps...
like a howitzer recoiling.....

 

I did notice that, and forgot to mention it. Check your motor and transmission mounts, I'd bet they are toast.

 

I noticed that too, wasn't sure if it was normal but definitely looked like there was a lot of tension. So you're saying this could very well be the reason for everything failing over and over again? what could be the cause of all this tension? What can best be done to fix it, tighten it all down, and prevent it from happening in the future? should there be no movement on that rear axle during acceleration?

 

I'm assuming that softening my driving style will greatly help prevent further wear and tear correct?

 

.. Axle wrap is pretty much a given with the stock soft springs, adding weight and liberal right foot make it worse. There isn't a "tighten it down". You need to make sure your motor and transmission mounts are in good shape. Then get some HD springs for the weight. If it's still a problem, then there is an anti axle wrap mod you can do that essentially u bolts the front of the leaf pack to the much beefer overload spring.

 

I apologize for my lack of mechanical knowledge but I'm unsure what is meant by "axle wrap". These springs are less than a year old, pieces of garbage OME Dakars that sunk instantly after install. Could a lot of this be due to the sag in the leafs? I'll go check on my mounts and check back...

 

Some level of axle wrap is a given with leaf springs. That seems to be the least of your problems. After looking at what others pointed out, I would suggest the following, and you need to do it all, not just one thing and hope the next is not a problem. Assuming you have a 3.4 DCSB w/AT, but your profile is missing that level of detail.

1) Get your driveshaft checked and balanced by a driveshaft shop, not a buddy that owns a jack and some wrenches and hammers.
2) Replace the carrier bearing ($69 Dana/Spicer, RockAuto). Maybe have the driveshaft shop do this while they are messing with the driveshaft.
3) Replace motor mounts ($16 x 2 RockAuto)
4) Replace transmission mount (~$25 RockAuto)

Parts here are less than $200, not sure what a driveshaft shop would charge. You've got so much crap moving around that there is no way anything is going to hold together for long until you get all the important contact points solid and eliminate any driveshaft vibration due to imbalance or improper assembly.

 

Axle wrap is the twisting of the axle under load (twists up) or braking (twists down).

Most people usually complain about the braking condition when they come to a stop- the axle twists down, and then once stopped, or right before the truck moves forward, will "pop"/"clunk" (unload) back to a neutral position.

The springs aren't crappy, I think you just have too much weight for them. You likely need a custom spring for your setup.

 

So many load the crap out of these....surely someone has a add-leaf beef up kit...

not for lift, but maybe one with extra HD clamp shackles...

Stiff rider.....