Rear End Bounce

[OVRLND_G8R]

No solution to it for me. But you may not be experiencing a similar issue. I would check driveshaft asap.

Buddy of mine blew his driveshaft on the highway. He was getting constant vibration and it got worse and worse. Unbalanced driveshaft can cause thevibration and if you bang it up on a trail it can cause it. Then boom. (Blown driveshaft also sheared off the output shaft of the transmission) Start there is my .02

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[steve68]

I found that adding a rear track bar relocation bracket helped. The rear suspension, if lifted, causes the rear track bar angle to increase and creates "bump steer" on the back of the truck. This would be a relatively cheap step to take and see if it works. I added the Teraflex to my 2020 gasser and it made a world of difference in ride quality. I have the Evo one on my '22 Ecodiesel.

This interests me,

Are we getting into a suspension geometry issue when there's added weight over the rear end, Is it a lifted angle increase and a weighted decrease of the stock suspension that now increases a angle which introduces a bump steer issue, and if this is a suspension issue tires springs or shock wont fix it, road VS suspension angles which in then causes a oscillating wave that the suspension cant over come, thinking out the side of my head here.......ideas thoughts, go pro mounts on the rear suspension???

 

[Pescatoral Pursuit]

I have the 3.3s and I'm experiencing the same issue. The 3.3s are absolute garbage.

I'm not happy with my 3.3s.
I saw a YouTube vid explaining the difference between digressive falcon shocks and progressive Fox shocks and if I understood it correctly, digressive shocks "come on" early then fade, while progressive shocks start travel easy then firm up, and the former is what my rear end would say its experienced on the trails.
I will say this: recently I was in a hurry and running a clay washboard trail a bit faster than usual and the shocks really seemed to come on and was the first time I was pleased with their off-road performance.
I was parked on a road one day between the order and delivery of my Jeep and watched this raptor go by and over a speed bump and the back bumper didn't move an inch. I was hoping to get this kind of performance from my suspension/ shocks but not close so far.

 

[jensjer]

Tis the problem with lifts..aftermarket anything.. If anyone is expecting to get "factory ride" even with all the correction brackets, highest quality lifts and parts ,... they're 100% wrong.
Nobody is putting in the hours that the actual engineering "teams" did.

 

[CrazyCooter]

Tis the problem with lifts..aftermarket anything.. If anyone is expecting to get "factory ride" even with all the correction brackets, highest quality lifts and parts ,... they're 100% wrong.
Nobody is putting in the hours that the actual engineering "teams" did.

I kind of agree with you here, but..........

You think the "engineering teams" really put that much work into the original product? Is that why Pilearis and CrapAm have bumpsteer actually built into the design? I'd this why Jeep has bottoming ecodiesel trucks out of the box?

 

[RedBearon]

Anyone ever find a solution or at least isolate the issue?

I'm here after doing a 2k mile trip from FL to CO and it seemed to only start around West Kansas.

I thought it was just that particular section of road but it seems to be doing it on many roads now (though not all).
I think I remember hitting a pothole a little while before it started but can't say for sure if that would cause anything to change.

I kinda thought maybe a wheel weight fell off but don't see anything obvious.

I'm on new 37" Baja Boss AT's setup on KMC Beadlocks.
Balanced just before I left on this trip and while not perfect.. seem smooth as long as the road is smooth.

Only other factor I can think of is my rear driveshaft hasn't been perfect since I banged it up on some rocks.. It vibrates a bit but not enough to cause the oscillation I'm feeling (I don't think at least) and that was 20k miles ago...

Wondering if there's an issue with the axel housing or shafts.

I'm gonna start isolating when I can.. but of course this happens in the middle of a 5k mi trip...

Things I'm thinking to check:

-Wheel Balance
-Rear Driveshaft
-Axel Housing
-Alignment
-Track Bar

I'll let y'all know what I find!

Update: Coming up on 4k mi into this trip and been paying more attention to the things that seem to affect it along the way..
Smooth roads = almost perfectly smooth ride.
Weight seems to be a factor.. when I was nearly empty gas-wise it seemed to have more of an issue... full tank smoothed things out.
This makes me thing it's more about suspension being unable to overcome the road oscillations... but hard to say without being able to swap out parts just yet...
Another 2k mi to go so wish my sanity luck!

 

[hickman785]

Hey all,

I’ve searched the forums, but can’t seem to find anything providing the solution to some rear end bouncing.

so far starters…. The mods
2020 Jeep Gladiator Rubicon
- 2.5” Clayton overland plus lift kit (comes with the triple rate springs)
- falcon 3.3 shocks
- 35x12.5 Goodyear duratrc at 28 psi
- smartcap, 270 awning, iKamper 2.0, fridge/freezer ( so a decent amount of weight which will only grow when fully loaded for camping trips)

What’s happening is when hitting bumps, mainly the segmented concrete highway, I get a bad bounce that is only up and down. No sway during this. It is repetitive and constant until the segmented Highway section ends and the truck smooths out almost instantly. I do notice the same feeling on side streets where it provides a similar situation.

I have adjusted the shocks settings messing with them to see if adjustments would solve the issue. No luck.
I’ve removed the weight from the truck, and it seemed to get a little better but did not solve it.

i redesigned the mounting of the iKamper to lower it closer to roofline to see if reducing the amount of air getting under the RTT would help, which it did but the bouncing is still present

are other people experiencing this and I am just being to critical on the truck?

Any advice, things to check, etc would be greatly appreciated

thank you

Ive been dealing with the exact same thing for over two years. I've spent almost $7000 trying to address it with no luck.

The only thing that helped alleviate the bouncing was removing all of the weight from the bed of the truck(about 600 pounds), higher tires pressures (lower tire pressure makes the bouncing unbearable) and when I tow my trailer it doesn't bounce...2 years into it and I've basically made no progress at all

 

[OVRLND_G8R]

Ive been dealing with the exact same thing for over two years. I've spent almost $7000 trying to address it with no luck.

The only thing that helped alleviate the bouncing was removing all of the weight from the bed of the truck(about 600 pounds), higher tires pressures (lower tire pressure makes the bouncing unbearable) and when I tow my trailer it doesn't bounce...2 years into it and I've basically made no progress at all

running the falcons I assume as well. I’m tempted to see if the 3.5s with the “auto” would solve it ?

 

[hickman785]

running the falcons I assume as well. I’m tempted to see if the 3.5s with the “auto” would solve it ?

I had the 3.3s and hated them...complete waste of $2000...I switched back to factory shocks and the jeep rides better now, but it still bounces...I'm looking at going with the Rancho 9000 adjustable shocks...

 

[bonner]

I'm having a similar issue. I Have a rubicon with the mopar lift. I put the EDC camper on it which supposedly weighs 300 lbs. As soon as I put that on ai started having a low vibrational bucking from front to back. To begin with I thought it was wind and aero dynamics but it does it at slow speeds too and its worse on the concrete highways. So I think it must have something to do with the weight and the suspension.

 

[FatBaldandWheeling]

Adding myself to this club.

I feel a little thankful that I found other people were having issues and have tried all the things I wanted to try to no avail. It saved me money. So, thank you.

I am running an AluCab canopy camper setup.

I have a working theory after moving from Teraflex 3.5" springs to Dobinson HD springs and seeing no change (aside fixing an inch of sag).

I don't think it's solely the weight, but how that weight is distributed. Most everyone I have seen as I skimmed this thread had roof top tents that were extending beyond the bed and over the cab.

You might know where I am going with this.

I think the Gladiator frame is engineered for flex to ensure it can off road well. With weight distributed beyond the bed, I think that the shake gets up through the chassis of the truck and into the camper and rent, and just as it settles from one bump, the next causes the issue. The flop is probably mostly in the rooftop tent.

For those who are just going with heavy loads, it is probably less emphasized but still present due to how the frame is constructed, if I were to guess.

I would bet the distance between the cab and the bed is varying wildly on these types of surfaces. I only have it on highway 285 near Denver. Any other highway is fine so far.

So, that is my contribution. This might be something I just have to live with. But, I am going to encourage my dealer to look at my frame to make sure nothing is starting to stress as a result of this bounce.

 

[JTGuy]

The frame on the JT is stiff and there is almost no flex in it. I have a ARE camper and have flexed my JT to the max and the camper never comes close to the cab. I had some rebound issues with my rear and got some Fox 2.5s with remote res and adjustable that were tuned by Accutune that has helped with the rear rebound some. He softened up the valve stack but with them being adjustable I can live with it.
The real issue as I see it is the way the rear shocks are mounted laying down forward. The shock mounting point on the frame allows a lot of the bed to be rear of the shocks. Too much leverage to the rear to control rebound.
I just don't like the way my JT rides, stiff even with the Fox's on full soft. I don't know if it's shocks or springs and no one seems to be able to tell me. Looking for a suspension person that will ride in it and tell me what to do. Or just tell me that's the way they ride so live with it. The freeway is fine but any bumps on a street or dirt road is bad.

 

[FatBaldandWheeling]

The frame on the JT is stiff and there is almost no flex in it. I have a ARE camper and have flexed my JT to the max and the camper never comes close to the cab. I had some rebound issues with my rear and got some Fox 2.5s with remote res and adjustable that were tuned by Accutune that has helped with the rear rebound some. He softened up the valve stack but with them being adjustable I can live with it.
The real issue as I see it is the way the rear shocks are mounted laying down forward. The shock mounting point on the frame allows a lot of the bed to be rear of the shocks. Too much leverage to the rear to control rebound.
I just don't like the way my JT rides, stiff even with the Fox's on full soft. I don't know if it's shocks or springs and no one seems to be able to tell me. Looking for a suspension person that will ride in it and tell me what to do. Or just tell me that's the way they ride so live with it. The freeway is fine but any bumps on a street or dirt road is bad.

The shock positioning makes a lot of sense, actually. Good call.

 

[JTGuy]

There was an issue a while back where JTs had bent frames from the rear shock mount to the rear. I think they had too long a rear shock so when it fully compressed it became the bump stop and bent the frame. Note that the Wrangler rear shocks have a totally different mounting and are better.

 

[Free2roam]

Didn't read every single reply. But did you upgrade your rear sway bar? I have the helwig I get no bounce.

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