Not really Urgent, BUT...

**bigdaddydiesel** · 09-27-2008, 05:50 PM

The truck I just bought has only ONE weird problem that I have never seen before. Here goes, and ANY suggestions or comments are accepted...

The Wife and I took the kids to the mall today in the new rig, the '02 3500 dually and we went via the highway. Well, here is what has me baffled, everything rides and runs good until I get to 78 MPH, then I get a vibration in the seat of the pants/ through the seat but not through the steering or suspension. However, it goes away when I reach 85 MPH. Also, it has the 5spd Allison, but the tranny temp never gets above 150* and the fluid level is fine...
I was thinking u-joints, but I was thinking that if it was the u-joints or the drive shaft being out of balance then the vibration would be all of thee time regardless of speed?...

There are absolutely NO other problems at all. I don't get it???
Anybody ever had this???
Thanks
Chris

CEB0217 · 09-27-2008, 06:15 PM

Have the wheels checked i had a bent one with almost the same feeling

(or try slowing down ha ha)

**bigdaddydiesel** · 09-27-2008, 07:19 PM

hahaha, I hear ya, I don't usually drive that fast, but it was the first trip on the highway and since I will be using this truck to haul those loads of trees, I wanted to make sure nothing was wrong that might cause problems under a load...
I will probably put a new set of tire on it to begin with, MAYBE even some rims if they are bad...
we'll see, and thanks for the advice!!!

Luv4chaos1 · 09-27-2008, 07:32 PM

One of your rear tire is out of balance....

DuramaxOnTheBrain · 09-27-2008, 08:59 PM

Does the frequency of the vibration match the "chugging" of the motor? Mine does this exact thing only im not sure what speed but it matches the rpm's of my motor.

**n0useforaname** · 09-27-2008, 10:21 PM

Never had my truck that fast.....but I would have to agree with these guys....it's probably the tires. I was once told that when tires are balanced.......they are balanced to be perfect up to 55MPH....anything after that is luck.

**BigRedChevy** · 09-27-2008, 11:41 PM

I agree with everyone else you have a tire out of balance. Should be a rear since you felt it in the seat.

**bigdaddydiesel** · 09-28-2008, 04:50 AM

Quote:

Originally Posted by DuramaxOnTheBrain

Does the frequency of the vibration match the "chugging" of the motor? Mine does this exact thing only im not sure what speed but it matches the rpm's of my motor.

It seemed too, that is what confused me, is that at first it did not FEEL like the tires, but of course it has been a while since I had a dually that fast and the last one never had tire issues so they are probably right, not to mention that I just bought the truck and although the other owner took extremely good care of it I only saw one receipt for the replacing of tires. No other receipts for balancing or anything for the life of the vehicle...
But it had receipts for everything else you would expect, and the worst problem it had other than having the injectors replaced under warranty in July was the tranny gear position indicator due to a faulty control module that froze in the winter.

So I guess I need to check the tires then...

I have to admit though, that is pretty good if that is my only problem right?

**bigdaddydiesel** · 09-28-2008, 05:02 AM

No doubt, I have gone through it and so far it seems to be Cherry! All of the fluids look good, etc, etc.
It does need shocks though, 116k and it still has the factory shocks so that has to be changed but everything else looks good ...

CEB0217 · 09-28-2008, 11:36 AM

When I have mine rotated they only use to balance the front ones but now i make them balance all of them cuse they can also tell me if i bent another rim