Rear axle wrap problems

[Dr Farnsworth]

Ever since I have had this 78 F250 it has been hard to get it moving without it lurching or hopping when the clutch starts engaging.

Someone noticed that my rear axle rotates up quite a bit when I take off and I was able to verify it tonight. I checked and could not find any broken springs or U bolts that were loose or broken.
For some reason there is enough spring flex to let the rear axle twist and cause this problem.
It has a Dana 60 if that makes any difference.
Is this a common issue, and is there a standard fix?

Some kind of traction bar would probably take care of it. But I don't want to go that route if there is a better solution.

[cep62]

Are you sure you're not experiencing clutch chatter ?
that's caused by a glazed flywheel , and sometimes can shake something fierce.

[eggman918]

FWIW that just seems odd to me with as thick as the spring pack is in the rear of an F-250 if there is nothing defective with the springs/shackles.

[basketcase0302]

Another vote on a glazed flywheel causing your clutch issues.
And like Steve pointed out very few issues with the springs, (unless thee truck has been used to haul it's entire life and the springs are worn out-or it has a broken leaf hiding in the spring pack). I'd also inspect motor and tranny mounts to make sure they're not broke.
You can add a simple traction bar to the top of the leaf pack, (rather than a ladder type bar that wraps around the axle tube) easily and for a lot less than ladder bars if you went that route. I had a set of these on my EB that I used to launch 3'-4' off the ground that held up well:

[Dr Farnsworth]

I double checked and it is definitely axle hop/ twist.

Motor mounts seem to be ok. You can watch and hold on to the gear shift when it's "hopping" and it does not move. That is typically a good indication that it's not a bad motor or transmission mount.
I also thought it might be the clutch grabbing or even Z bar linkage slop. I tried taking off in third or fourth gear, revving up the engine and slipping the clutch. The clutch engaged smoothly, so I don't think that's where the problem is.

Ford used cast iron lifting blocks to raise the truck for the 4X4. Those blocks would definitely magnify spring twist.
It's totally baffling to me that an F 250 that was rated to have over 8K GVW would twist like that. Instead of a traction bar I probably should look at new spring packs.

[basketcase0302]

Or have your OE springs re-arched and have another leaf added which can a lot of times be cheaper and accomplish the same thing-stiffer suspension. I remember those cast iron blocks and had several different variation of them at one point from a 1/2" to 1" wedge to the 3" solid steel blocks.
I can see it eating u-joints if it got worse-nice truck BTW!

[Bill Ramsey]

I would try some stiffer rear shocks, first.

[BobbyFord]

Housing rotation is different than leaf wrap.