Wobble/Bumpy Feeling

Hey everyone, so I’ve been trying to chase a problem down for a couple of months and I’m not sure what it might be. When driving on flat pavement and getting up to speed, my truck feels like it will start bouncing or wobbling. Kind of like going over small whoop section. The ride has also been a bit harsher in the front but the bouncing feels like it’s coming from the rear (I can feel it in my seat).

So far I have tried:
- Alignment
- New Wheels and Tires
- Balanced (twice)
- New brake pads and rotors

One theory is the driveline since I added a slightly heavier RTT in the rear which lowered the rear end significantly. I may try a CB drop to see if this alleviates any of it but the feeling comes whether I’m on the gas or not.

Any suggestions?

 

You definitely tried the obvious, so here's what I would check next.
Driveline, as you stated
Any of your half axles bent
Damage to one of your knuckles or bearings
Tie rod slop
Ball joints
Sway bar

 

Thank you, I’ll check all this out. I would think during the alignments they would have checked tie rods but who knows lol.

 

Good point. And you'd most likely feel it in your steering wheel too.

 

Lifted?
Tire size?
Any changes to rear suspension from stock?
Mileage?

Soumds to me like rear suspension not holding up.

Without more details hard to suggest anything. For my weight I carry I added firestone air bags. Might not be your issue. More details.

 

2” lift in the front and it’s on 3” lift leaf springs (All Pro Standard 3” not rated for weight) but is lower due to weight of the RTT. I’m currently on 285/70/17 and was previously on 285/75/16 but I’m not sure if the problem is worse/same/better with the new wheels and tires. I also have dobinsons MRR long travel shocks in the rear with superbump bump stops. Currently at 61,800 miles.

That’s another thing I’m thinking is that the leaf springs are bouncing too much since there’s too much weight for them? With the super bumps in like 0.5”-1” off the bump stops.

 

I have set my dobinsons to the lowest they can go on everything and the highest they can go with very slight changes in the bouncing feeling

 

How old are your shocks? If one fails early, it can fail to adequately dampen your springs.

Example video.

https://m.youtube.com/watch?v=jLhXeUo6z7k&pp=ygUXYmxvd24gb3V0IHNob2NrIGRyaXZpbmc=

 

Both are a little over 2 years old. Eibach Stage 1 in the front and dobinsons MRA in the rear

 

Is the tent the only weight in back, and if so how much does it weigh?

What other weight if more than just the tent? Did you add a rack for the tent or was a roof rack already on the truck before the tent?

How much did the rear sag when you added the new tent?

It sounds like this started as soon as you added the tent? If so, a tent alone should not create much sag.

BTW, no lift here. Bilstein 5100 front and back and the rear air bags. Here is my truck with just my toolbox (300 pounds) and my 265 75 16 BFG E load spare. Only 18 lbs in my air bags.

If I load the truck with 800 pounds in the rear, I can lift the rear higher than this photo with only 35 lbs in the air bags. My leaf springs are original OEM with 75K miles on them, and close to 30,000 off road miles. No issues. With 800 pounds in the rear, the air bags make it feel like and drive like an empty pickup. Super stable.

 

I have a bed rack, steel rear bumper, steel gas tank skid plate, and the tent in the rear. The bed rack is about 61lbs, the bumper is 81lbs, not sure on the skid plate, and the tent is 160lbs. Around 300+ lbs of constant weight. Not sure if it counts as “rear” weight but I also have steel sliders.

Air bags seem like a good idea since I do sometimes haul heavier stuff in the rear. Do you do more technical off-roading like rock crawling with them, if so I’m assuming they’ve held up great.

 

No rock crawling. A lot of deactivated roads as there are so many of those in BC that lead to remote fishing lakes. I am retired, no interest in “technical” off roading. All trips for the purpose of going to or trying to find access to remote lakes.

Lots of washouts, bumper dragging etc. Lots of this stuff.

 

Sounds to me like your rear suspension needs a refresh. Get leaf springs rated for extra weight and see if that fixes it, if not I'd get different struts too.

If its the rear end that's bouncing, that's all it could really be right? I noticed my leaf springs finally called it quits on me, used to hold my gear and motorcycle fine, but now it sags pretty good in the rear. Not bouncy, that I've noticed but...needless to say I'm getting some custom Alcans made this winter.

 

I’m assuming it’s the rear as I feel it in my seat. The best way I can describe the feeling is hitting small whoops or like a knot in the tire. It seems like it happens when I get around 30-50 mph and gets worse with more speed but goes away on the highway or driving slower.

I’m definitely looking for some new springs. I’m installing a CB drop kit this week to see if it at least changes the feeling or anything to rule that out.

 

Had the same feeling in mine, added a BedTT and after 6months a significant squat started to appear and even the front springs were sagging.
The word i had for it was squirrely, at freeway speeds hitting a new section of pavement would cause a bounce and as the nose raised up the steering wheel would wobble.
Was getting driveline clunking too
Higher constant load springs fixed the squat and the fronts went back to the original lift height, and now the clunk is in the front =P

 

A sagging rear will unload the weight off the front, and even more so over inconsistencies in the road you can barely see. I had a spacer lift on OE springs, after adding a fiberglass topper and a Decked (total about 330#) I had a horrible highway ride, unsafe at times over bridge expansion joints around curves at speed. I would hit the OE bump stops often. I replaced with Icon RTX on stage #3 that fixed it all, no porpoising, excess body roll, and hitting the bump stops.

 

Thanks everyone, so far my plan of action to eliminate it is:

1. Check front and rear wheel bearings
2. Check tie rods
3. Check CVs
4. Install CB drop kit
5. Grease U-Joints
5. New Leaf Springs
6. New shocks

 

It's sort of been discussed, but did you inspect your rear shocks to see if they are leaking/blown? Quick to diagnose, and free to check. I blew one rear shock at around 10k miles when I was loaded heavy in the bed for a trip to Moab. Spent the week in Moab wheeling with it, and fixed it when I returned. Any little bump in the road caused my whole rear end to bounce and oscillate a few times before coming back to rest. One working shock wasn't enough to dampen the leaf springs so it bounced all over the place until I replaced it. The blown shock that I pulled out was clearly leaking (and if it leaks, it's blown, they only need to lose ~10% of the fluid to become basically worthless) and I could compress it with almost no effort with my two hands when I took it off the truck. I'd move it up your priority list since it takes 30 seconds to crawl under the truck to inspect for leaking, and if you want to be sure, just remove both and try to compress them, which also takes just a few minutes.

 

I just inspected them and none of them seem like they’re leaking. I also did a bounce test and put weight on the front and rear to see the rebound and it seemed normal, no weird bouncing.

I just checked the CVs, tie rods, spindles, and tried shaking the tires with my hands at 9 and 3 on all tires and nothing seems like it has abnormal play. The driver CV has a little more play than the passenger but after doing some research this seems normal.

I also installed the CB drop kit, so I will see how it feels on the way to work tomorrow.

 

On another note though, I noticed if I spin the front tires back and forward quickly I can hear a little click on both sides, I’m not sure if this is normal. Also I seems like my front brakes (just replaced pads and rotors with the power stop kit) are constantly slightly touching and I can hear a slight “hiss” when spinning the wheels. Not sure if this is normal either