GEN 1 CONSTANT vibration while driving

[Mike175]

Put a big breasted woman in the passenger seat, sit back and enjoy the jiggle..



Had the same thing in mine. I felt it around 50-60mph through the truck not in the pedals or wheel. It could be so bad the rear end would hop. Alignment, new driveshaft, balanced wheels and shaft didn't fix it. Rotated tires, ran another 2K and it's gone. I suspect mine was uneven tire wear. It took a bit to even it out and it's gone.

 

[All The Way]

As for bouncing while towing, check for a bad rear shock.

 

[KingRoman]

As for bouncing while towing, check for a bad rear shock.

Is that possible with 20k miles and virtually no heavy loads, towing, or any serious off roading?

 

[Fuzzy Dice]

Nv Guy is on the right track, I think we need more info to help out. Like he asked...

Is the vibration speed sensitive?
If you rev the engine while in neutral/ park can you make that vibration increase?

Also I know you said it's constant but does it pulse heavier or lighter at any point? Does it change if you're going around a corner, like taking an on-ramp?
Is there any difference when you're accelerating, driving at constant load, or decelerating/coasting?

 

[KingRoman]

Nv Guy is on the right track, I think we need more info to help out. Like he asked...

Is the vibration speed sensitive?
If you rev the engine while in neutral/ park can you make that vibration increase?

Also I know you said it's constant but does it pulse heavier or lighter at any point? Does it change if you're going around a corner, like taking an on-ramp?
Is there any difference when you're accelerating, driving at constant load, or decelerating/coasting?

Revving while in neutral / park does not make it increase. It almost feels like a super small misfire at idle, and with any more gas its smooth.


The vibration is speed sensitive. From 55-65 mph it is the worst. With a trailer on (2500-4500lbs) the vibration is much worse at the same speeds as without a trailer.

Anything above 55 mph on the highway the truck will not relax, myself in the driver seat is literally shaking the entire time. Steering wheel is shaking too. Passengers in the back seat said it wasn't that bad, but up front I can definitely feel it much more.

Tried 48 to 36 psi and its all the same.

Dealer said to bring it by Thursday and they will take a look.

---------- Post added at 09:54 PM ---------- Previous post was at 09:51 PM ----------

Is the vibration speed sensitive?
If you rev the engine while in neutral/ park can you make that vibration increase?

These trucks have lots of harmonic dampeners- these are the chunks of iron that you can see under the cab, there is also one right above the spare. Anyway, if you lost one or more of them you may be feeling a harmonic vibration more than an actual "bent drive line" sort of thing.
Now, the violent hopping when towing? That may be a whole 'nother issue.
How heavy a trailer? Are you using a weight distributing hitch?

Yes it is more severe when I am towing.

Last time I have towed was a few weeks ago with just a trailer and one UTV on it. Not sure how heavy, maybe 3500lbs? It was bouncing pretty badly. 55-65 being the worst.



No WD hitch. I checked for the harmonic balancers, actually only confirmed the one on the rear frame rail under the bed is there, and the rubber mounts seem to be supporting it fine.

Threw my stock leaf springs in the bed for now to see if some weight helps settle the truck down a bit -- but it really hasn't done anything.

 

[Nv Guy]

Wow, lots of things going on here...
Since the engine doesn't seem to get worse when revved up, i am going to discount an out of balance cause there (torque converter / harmonic balancer).
First, verify tires / wheels are properly balanced & true. And that they are not installed by some over zealous guy with an impact.
Now, the vibration when towing. I wonder if you have a U joint going, as the drive line angles will change when towing. As previously mentioned, I also suspect the rear shocks may be shot which would account for the bounce when towing.

 

[MatMan]

Rear axle? U bolts loose?

 

[KingRoman]

Wow, lots of things going on here...
Since the engine doesn't seem to get worse when revved up, i am going to discount an out of balance cause there (torque converter / harmonic balancer).
First, verify tires / wheels are properly balanced & true. And that they are not installed by some over zealous guy with an impact.
Now, the vibration when towing. I wonder if you have a U joint going, as the drive line angles will change when towing. As previously mentioned, I also suspect the rear shocks may be shot which would account for the bounce when towing.

Thanks I'll mention to the service writer for them to look into the driveline / ubolts as well.

I'm dropping it off Thursday, going to have them do an alignment as well just to see, etc.

 

[Ironhorse07]

I'm thinking bad tire. One of them has a bubble or ply separation.

 

[Ditchplains1]

Not to miss the obvious, but power steering going bad? Bad IWE?
Eddie