It's interesting --
I presented the problem on several boards.
In sumation:
Lots of replies "never hear of that."
That shows it isn't a common problem - or those responding never get out of the parking lot. Take your pick.
A few replies "heard of it, never saw it." AHA, it's existed before, so it's not something unique to mine.
And a few responses "adding a lift kit cures it." Hmmm, must be something that got replaced in the process.
A few more "Try decent shocks, like 9000's. I know that will help some, but it covers up the problem, not cure it. I'd like to cure it first, then use heavy dampening.
2 said "it's the driver." I rather doubt that, considering my experience and the fact the rest of my 4 wheelers - 5 others right now - have no problem with that hill. Lost count years ago, but I've owned and wheeled somewhere around 25-30?
One guy has nothing better to do than count the number of Jeeps he's "seen" -- see above a few posts.
Another thinks getting innane responses with no suggestions, then posing the hop problem again is whining.
And the kicker - I referred to early Bronco suspensions - he must not have been born when the early Broncos were around - or under a rock. DUH!
The nitty gritty:
1. Have a look at the Panhard. Notice the ends are not at equal height above the ground when sitting flat. When the axle travels up and down, the panhard will rotate around the center where it's attached to the frame. As the Pashard travels up and down through it's arc, it pulls the axle with it from side to side. If it's flat - both ends equal - the arc it goes through pulls sideways very little.
But if the ends are not at equal height that arc is greater. That's the source of the bumpsteer -- I never even mentioned that! Try it on a paved road that's not perfectly smooth - at speed, like 80 or 90. You can hardly keep it on the road due to the bumpsteer.
It's very sensitive steering to start with - factory has the caster set too negative -3. I gave mine +2 - what a difference!
But the Panhard needs to be lowered at the frame end, or raised at the axle end. The Panhards are wrong at both ends of the vehicle. I'll fix that once I've lifted it a bit, probably going with 3" and a little body cutting.
That's part of the hop problem, the axles shifting sideways a tad. But not all of it.
Squat - Think about the front end. When under power the axle wants to rotate in the opposite direction from tire rotation - blame Isaac Newton for that. We all now a rear pinion wants to riase up under load, the front pinion, being on the rear of the axle, wants to rotate down.
But - since the axle cannot really rotate (wrap) like with a leaf spring, it pushes the radius arm(s) downward. On a flat surface with good traction you'd see the body get pulled down by the arm's ends. The body will actually drop -- or "squat." But another way to think of it, it's trying to lift the front wheels UP in relation to the body/frame.
Now on a hill - weight transfer lightens the front end anyway - making the following easier to happen. Under hard acceleration up that hill the arm pushes the frame down - think of it as the opposite - it's LIFTING the front wheels!
Simple - wheel lifts, loses traction (thus losing the reason it was lifting - Newton again) drops back to earth, grabs, lifts again - hop hop hop. It's the inherent design.
The upper links at a slight angle help some, better than the Bronco that didn't have them, but still it happens.
Longer arms and or a lower mounting point help reduce the squat a little. Notice those goofy looking Ford trucks that they lift waaaay up. The arms front and rear are next to each other and hang down way down. Otherwise hop's terrible even in a school zone.
And why mine was worse than most? I'm sure the broken factory weld that looked good on the arm's mount contributed quite a bit. That was a 5 minute fix once I saw it late last night. The weld looked OK, but it missed -it was next to the joint. Since it was so clean and painted there was no rust line to help find it. I was lying under it with TJ right next to it comparing angles and such when the light hit it just right.
The rear - same as the front but instead of Squat, it's called Anti-Squat. Get the front bouncing and the rear starts it - what a ride! You still see those rides sometimes in front of supermarkets, usually costs a quarter.
And - one more contributor - a coil spring has a fairly flat rate factor. In other words a 175 lbs spring takes 175 lbs to compress 1 inch. Another 175 lbs it'll compress another inch, or close to it. And another 175 gives another inch - it's a linear curve. That gives a nice soft ride.
Leaf springs are a progressive rate, adjustable by material, leaf thickness, width, length, taper, end taper etc.
A 175 leaf does the first inch at 175, but to compress it another inch it needs more than adding another 175 - maybe 250, then the next inch needs another 350 etc. So it's progressive. The progressive effect dampens the wheel hop problem to the point it's fairly uncommon - but - they wrap - an entirely different problem!!
Soo - check the welds veeeeery carefully! Replacing the rubber bushings with Urethane should help a little, takes the wiggle out.
Heavier coil springs - the Rubi's are light for a nice soft ride - as the service manager at my dealer says - "most Rubi's will never see the dirt."
Dampen the hell out of it with good shocks.
Add a little more positive caster.
Use tires with more sidewall flex, the stock 16's are stiff.
Lower air pressure to help dampen.
Get the Panhard flat.
I'd bet the reason the "D-44's" are hybrid D-44/D-30 is to keep unspring weight down a little - factory's aware of the hop. That unspring weight is a real killer.
And - ignore folks that think repeating a question is whining.
There are other things that could use improvent on the Rubi - but not as major.