Ive read on here before about this mysterious vibration that comes on at like 76mph and then fades away at about 78-80. My truck has done this since i purchased it. I have changed front shaft, rear joint, flex coupler, all tires, shocks, t-case with no change in this vibration.i do howevernotice that it seemsto beless intense if at this speed the windows are down.Is it thatmost owners neverget to this speed and its more common than not? or theaerodynamics of this truck at this speed make it shake a little?Any ideers??

 

Mine does it at about the same speed but mine started after
I had the tires balanced.
If you have a off-road tires you could get the road force test done to see if you have a tire that is out of round or rolls much different than the others the road force test will tell.

 

same problem here with an 03. I have had suspension components looked at, tires balanced, alignment done etc....I am interested in what everyone has to say!!

 

2 diff sets of tires, no difference. Now im one to change things that could be suspect but all that really left are the cv's and hub assem. none are cheap guess's

 

Why are you even driving that fast?
You will get your best MPG at 65 and it wont add much time, if any to your trip.

 

well for a while i was making 6+hour trips up the eastcoast and the whole nj turnpike travels about 80, then going south like through north carolina they move through there as well. and its bad on gas any way you look at it, but more importantly i doubt they sold the truck like that.whether i drive at that speed again i still like to gather input about what causes it.

 

I agree that the truck shouldnt shake at any speed. Mine doesnt, it wanders, but does not shake.
You have already done everything that I would do to try and find the problem.

But for the sake of argument, 500 miles one way at 75 will cost approx. 36 gals of gas and take approx 6.5 hours.
Same trip at 65 uses approx. 28 gals of gas and take approx. 7.5 hours.
That is a difference of approx. 8 gals of gas and at $2.50 per gallon it will cost you 20 more to drive 75 vs 65.
So round trip costs you $40 more but saves you two hours.
When gas goes back up to $4.50 per gallon, then it will cost you $36 one way, $72 round trip.

You can do what you want, but personaly, I would rather spend that money on something other than gas.

 

97 saab 2.3na 1000 bucks 34mpg highwaywith 87oct it still just love the rover, even if its 15 on93..

 

We are the same with the Volvo, 35mpg expressway @65 and it seats 7.
We use premium it that too. Recommended but not required.

 

rite on.