Vibration when going 65-70 mph

[GenLee01]

Hey guys. Tell me what you think. I took my X to work and on the highway when I got up to 65-70mph it shook pretty bad. Any ideas what this maybe? The only think I could think of was out of balance. I need new tires (30x9.5 is what I am thinking, stock 94 sport with molding on fenders) and was wondering if might cure the problem. Any ideas????????

 

[alphasylum]

Crazy thing you ask that question.
I experienced the same problem.
It only happened when I was between
65-70, if you went faster it went away
and if you went slower it went away.
I came to my own conclusion it had to be
something during that gear. I was told
to wait for my firestone replacements ...it wasn't that,
when I was told it was normal vibration I laughed and said uuhhhh NO. Then they mysteriously found out it was coming from the rear and it was the differential. Parts took 1 month to come in....it took 1 week and a few days after more parts came in to have it done.
Finally smooth sailing.....

Not to say that's your problem but crazy coincidence because this only happened to my x at 65-70

 

[GenLee01]

alphasylum

alphasylum

Do you know what they did to the differential? Who did you take it to get fixed? Did you go to a garage or to a dealership or did you do it your self?

 

[alphasylum]

I'm still within my extended service plan so it was covered through the dealer.

 

[oceanworker]

Vibration isolated to a range of speed can be cause by tires out of balance, driveshaft out of balance, u-joints need replacement, or differential problems.
Take your truck up to the speed where it vibrates and engage the clutch. Does it still vibrate? Does the vibation occur when deaccellerating back down from 75 or only under accelleration up from 60?

 

[ToneDog]

I had a '91 for almost 6 years and must of heard a million different resolutions for the same problem, it's funny but because of the design of these trucks the slightest of balance item can get the whole thing shaking !

Well From my experience and I had alot of shaking with that puppy! I found this (in oder) :

#1 Balance the tires, BUT!! Just don't get them balanced actually go to a small shop and watch the guy do it for ya, I had my tires balanced 5 times and only once were they balanced correctly, when I bent down and watched the tire spinning on the machine and made sure I didn't see any bouncing comming from the tire.

#2 Check your suspension, old shocks loose gas at different rates and one shock can end up being in better/worse shape than another

and finally, what fixed my 65-70mph shake

#3 a new set (all 4 tires) of Michelin XC-4 from Sears that were balanced 3 times before I let them put them on the truck (BALANCE BALANCE BALANCE)

The truck was like glass from 0-100mph (oh yeah and i had pretty new shocks on it too)

Don't forget !! Rotate those tires often and BALANCE them every time you rotate and you will stay in "GLASS Mode" while driving 65/70mph!

Because if you don't the vibrations will return! !

This is only my story on vibration, like I said there are 100 diferent stories!

Good Luck
ToneDog

ps check out this site Dead Link Removed

 

[GenLee01]

oceanworker
Thanks for the suggestion. One problem it is an automatic. Any ideas on that?

ToneDog
Thans for the suggetions. I know it needs new tires and shocks wouldn't hurt any. I want new ones so hopefully I can replace them too.

alphasylum
Did they tell you what they did under warrenty to the truck?

Thanks for everyones help. Any more suggestions from anyone is helpful as well. THanks again.

 

[oceanworker]

If you need tires anyway, hopefully that is the cause of your vibration. I once had a belt slip on a tire w/ only 20K miles on her and it set off on hell of a vibration at high speed. Also I had a bad rim that cause some balance problems.
If you do most of your driving at high speed (like I do), ask the tire technician to balance your tires AT that speed! Also tell him about your balance problems and watch him balance them, tell him you need an accurate balance. My tire guy hates to see me coming for a rotate, since I work him to death on the balancing.
Let the board know what fixes works.

 

[oceanworker]

I forgot, if you have an automatic, bring it up to speed where it vibrates and put it in neutral. Does the vibration quit?