Hi,

I'm new to the forum but I have been a Dakota owner since 1998. Since my '98 I've had a 2003 and now have a 2008. I'm experiencing a vibration issue and wanted to see if anyone has any ideas. When you accelerate above 35mpg the truck develops a medium frequency vibration that appears to be in the front half of the truck. It will continue up to 45mph and then can't be felt at anything above. Pressing the brakes has no impact, nor does taking the truck out of gear. The vibration which is to fast to be tires can be felt between about 35 and 45 regardless if I am accelerating, decelerating or out of gear. I thought it might be a universal joint and took it to a mechanic friend who checked all of the universal joints and the hangar bearing and said they were all smooth. He agreed it wasn't tires but didn't really have any ideas other than something in the transmission or differential.

I'm tempted to just drive it until it gets worse but I thought I would ask and see if anyone had an idea.

The truck is a '08 2WD, 3.6L, Extended cab and it has 31K miles.

Thanks for your ideas!

Jon

 

Easy solution to start with would be swap the front tires to the rear, if the issues goes away or moves to a different speed, it is likely the tires out of balance or wondering tread.

 

The tires have been balance and I'm pretty confident it isn't tires. The frequency of the vibration is much higher than the rotation of the wheels.

Jon

 

Do you have these steel wheels?






I have the same vibration and wheels, still get it no matter the front/back/left/right rotation, and I'm beginning to think it's a harmonic problem with the wheels themselves. I had recently discovered something that I think backs this up: After noting my tires were developing a wear pattern indicative of overinflation (I kept them at 30psi cold per the door sticker, but they were still wearing in the middle much faster than the edges), I dropped them down to 26 to see if it helps the wear rate. One thing I did notice instantly after making the change was that this "vibration" was less harsh.

That pretty much confirmed to me it wasn't drivetrain (tire pressure shouldn't affect any u-joint or bearing as the drive angle wouldn't change). But this gave me a theory: There is a natural harmonic coming from the these particular wheels, and firmer tires tend to transfer the vibration to the vehicle much more than softer tires, which tend to dampen it.

Thoughts?

 

Balancing your tires wont cure a vibration that is caused by scalloping or cupping of the tire, nor will it stop vibration caused by shifting belts. Rotating your tires in your driveway is free, i would give it a shot.

 

I like this conclusion a lot. Reminds me of the muffler drone issue. Basically the vibration from the road matches the resonant frequency of the steel wheel, or other suspension part and the steel wheels just transfer the vibration better than alloys. It would be interesting to see if plasti-dipping the steel wheels would solve the problem, or lessen it.

 

I have the same wheels, Not a single issue with them, other then when I had 2 inchs of mud packed to the inside of them.
I run my tires at 32-34psi Also I go by the Tire Pressure marking on the Tire, Not Truck. My Spare Tire is marked at 42psi.
Both my Summer Tires and Winter Tires Both run at 32-34 As Both sets are Mud/Snow Tires. But my Spare is only a All-Season.

Tires are marked themselves as per what they are manufactured to run at for best performance/traction/wear

 

I have alloy wheels and not the steel. I'll try altering the tire pressure today and see if that has an impact on the vibration. I'm still not sure how tires or wheels can cause a vibration several times faster than the revolution frequency of the wheel. Its similar to the vibration you get when you drive over ribbed pavement on the side of the interstate at 60mph.

Jon

 

Sounds like a tie-rod end to me. Once you are going fast enough, the tie-rod is pulled/pushed back to a stable position.

At speed, with no-one around, turn one way and then the other very gently. Does the vibration occur one way and not the other?

I waited too long with my last car and when I finally changed it, it came apart in my hands once I took the wheel off and grabbed it!

I think I have one going on my truck now.

 

crawl under truck and grab the driveshaft, if it wiggles back and forth, you may have a failing u-joint, or even the u-joint at the tranny yoke