Its not major but its definitely noticeable....right at around 115 it starts this slight shudder - what would be causing this? Anything major or just something a little off balance?

 

If it was something major you would know it. Go get your tires balanced and see if that cures it.

You might tell them you don't want the stick on weights, but the ones that go on the beed of the rim, but put them on the inside of the wheel.

 

Hmmm....what's the critical speed on our driveshafts? Anyone know. I remember a while back someone posted about 4.10 gears causing problems with driveshafts snapping at certain speeds. It was something like 80-90mph, with 3.73's it would be just a little higher than that.

Definately get the tires balanced first though like Flyer said before worrying about the driveshaft.

 

I had a similar problem and it ended up being a bad u-joint. I mainly felt the vibration in the dashboard and steering wheel. What I think happened was that the wear on th u-joint started causing a minor "whipping" effect on the driveshaft. How many miles are on your truck?

 

Was thinking the same thing.....
Esp at that speed
Any vib at lower speeds ? around 57 or 38 ??

 

only about 12k miles on the truck. The driveshaft had been removed when they pulled the tranny to install the yank 3k - but other than that it hasn't been touched. It doesn't vibrate at any other speed.

 

go to the dealer and tell them well i have a little prob.... my truck is vibrating at 115 miles an hour. i bet the face they would give you would be priceless. then they would be an *** and ask well how did you get it to go that fast it shuts off at 100.

 

HUH? that's scary. i broke 140 with a set of 4.10's with no vibrations whatsoever. tad bit of wind noise though.

 

No, my driveshaft blew up at 120 when it shifted into 4th, due to critical speed being exceeded. I used to get vibrations right at 110mph. Now with the Denny's drivehshaft, I have had it up to 135 with no vibration or problem, and it shifts nice and firm into 4th gear at 120!

 

geez! you guys know EXACTLY how to scare the **** outta me!... first its everyone talking about their trannies breaking.... now its driveshafts snapping w/ 4:10 gears.... you guys are gonna give me a heart attack, and they'll have to fly me home......

hmm....

... keep it up....