Wierd Vibration At 100-105 Mph

[99silverado1500]

Ok, yes I know I shouldnt be going that fast, but at 100-105 approx there is a wierd vibration, but it goes away when you go faster or slow down, and it happened twice. What would cause it to do such a thing? I Had it going 128 to see how my Hypertech worked, and I borrowed a set of drag tires that were rated for 160 or so i believe, but i had no noises or vibrations other then right around 100 for a short time in 3rd gear before it shifted into 4th. It seems to be sorta a mid chassis vibration. Any ideas

[mitchell87]

Wow, 128 that impressive

[99silverado1500]

Its not that much, but for a truck its moving pretty good

[mitchell87]

Its not that much, but for a truck its moving pretty good

 

 

For the average person i would say that is darn fast, heck even for me that is quite fast, I have only done 120, but that is because the car was limited to 120. But either way your right, for a truck that is pretty good.

[fbachman]

My guess is that it is a chassis resonance.... let's face it, I don't think the design spec included cruising at 128mph...

 

on that note... 128....wow...

[mitchell87]

My guess is that it is a chassis resonance.... let's face it, I don't think the design spec included cruising at 128mph...

 

on that note... 128....wow...

 

Are you sure?

[99silverado1500]

Yeah I know its not supposed to go that fast lol. I just thought maybe something was off balance since it is only at a certain speed, but I guess ill let it go since ill most likely stay under 100, as there is no real reason to be booking it like I was, but its nice to know what you CAN do lol.

[fbachman]

My guess is that it is a chassis resonance.... let's face it, I don't think the design spec included cruising at 128mph...

 

on that note... 128....wow...

 

Are you sure?

 

 

 

pretty sure...

[fbachman]

Yeah I know its not supposed to go that fast lol. I just thought maybe something was off balance since it is only at a certain speed, but I guess ill let it go since ill most likely stay under 100, as there is no real reason to be booking it like I was, but its nice to know what you CAN do lol.

 

The fact that it is, indeed, a narrow speed band is the tip-off for me that it is a resonance. If it started, AND CONTINUED as you continued to build speed... i'da thought it was something else...

 

[99silverado1500]

Alright sounds good. It was neat to see my speedometer pegged off at the mark past 100 and my gps climbing and climbing lol

[chevylobo]

i had my 97 up to over 100 i had same shake i think its gm's way of saying wat the hell are you doing ona side note my old 92 dakota would do 135 easy

[99silverado1500]

i think its gm's way of saying wat the hell are you doing

I wouldnt doubt it....

 

I doubt my tank will even do over 80 in the 1/4 mile so I wont ever really break 100 again, so its not anything to worry about since its only a resonance. Pretty f**kin scary when stuff is whipping by faster then you can see in a 1/2 ton truck lol I never expected it to move that fast lol

[svensk]

Drive shaft.

[strafingmoose]

128 ? Holy f.

 

I wonder if the 4.8 could reach that, not that I really want to try though ;)

[bennyray]

If you have ever been on a bike... 128 aint nothing. Although 128 in a truck is awfully fast, I'm guessing it has to do with the resonance of the tires and the frame and everything if its only at that speed.