I have a 2011 ford f150 4x4 I bought it used Why does my rear end bounce when im in the sand on a take off. And no I don't floor it on the take off.

 

Axle wrap or wheel hop.. What happens is the tires get grip on whatever surface they are on, but the leaf springs are too weak to hold the torque and bind up, then release when they get to a point that the tires loose traction...

Back in the day, hot rodders would put "slapper bars" on their hot rods to help this.

As the axle wraps, the slapper bar hits the leaf with it's rubber snub thing and then stops the wrap of the axle and plants the tires harder to the surface.

I've had the same problem with my 97 F150 and even my 13 F150. I put these on for other reasons, but it also did help a lot with the axle wrap issue spinning the rear tires on a slippery surface..



The shocks have helped some too I think..

Just what has worked for me.. I don't have that issue anymore..

Mitch

 

I have this issue on my F150 during the winter... I remember the first time it happened, it scared the junkers out of me. Doesn't happen all the time though.

My '99 never had the issue, I think because it was a super cab and there was more weight or something.

 

You probably need new shock absorbers. The factory shocks are pretty soft and they don't last forever.

 

What glc said, recently had a shock fail on the drivers rear of my truck and it has an awful bounce now. Put a PAIR of new shocks on and it should cure your ails

 

If you have good shocks, try reducing the AP a few pounds before you spend any $'s.. next, stop overpowering whatever your driving conditions.. pc

 

Something like a half leaf … etc to stiffen the long portion of leaf spring pack ahead of axle would help. The spring winds up a little under power and when tire traction capacity is exceeded, energy in wound up leaves is released in a snap. Was a wide spread issue with many leaf sprung muscle cars of old … even some coil spring cars would do it due to soft rubber control arm bushings, or just flexing stamp steel control arms.

Y'all do recall slapper bars and pinion snubbers?