ok so this has been getting to the point where i don't like driving my truck on the highway...heres the report...on the highway my truck shakes above 70-73 miles an hour....NEVER DID THAT before a week ago...i was able to get it up to 90 mph and it would run like it would at 50 mph...my rear veiw mirror shakes so bad i can;t tell what kind of car is behind me (they all look the same) if i let off of it and bring it down to 55mph, it sounds like my hubs are locked and im doing 130 mph. (they are not) then does the same thing when i bring it back up to speed (65-70 mph) at 65-70 it is fine and runs fine...driving it in town is like she has always been...nothing has changed, just at those speeds...im thinking its the tranny in 4th gear? i dunno its an 89 pickup eith the 3.0 and an auto tranny....please help guys

 

Tires, u-joints, wheel bearings...

 

Perhaps you threw off a weight on your wheel?

 

yeah the shaking=lost wheel weight.

As for the loudness, exhaust leak? blew out the cat?

 

its only loud when mentioned though

 

Wheels full of mud,ADD not disconnecting(front driveshafts aren't balanced well).What freq is the vibration?Slow and choppy or fast and buzzing?Airplane turbulence or Lazy-Boy?Does it have plenty of power?Swing bearing?

 

My truck did the same kind of shaking thing, but nooo noise. i dont know what to tell you about the noise, but check your ball joints. also, you wouldnt by chance have a bent axle would you? but before you check into that, have your wheels balanced, look for funny tread wear, and if you can, see if your rims are straight and true.

 

Belive me, I had the same problem with mine, and it was the u-joints.

 

hey keith where did you get your u-joints from

 

I had those EXACT same symptoms on mine. It turned out to be a bad rear driver side axle bearing. It was real bad at 50mph got better by 60 mph and then was loud as hell and shook violently at 65-70mph and up.

edit: re-read your symptoms and I guess they are not EXACTLY the same but pretty darn close.

 

I'd say U joint. with your truck turned off and out of gear go underneath and see if there is any play in the driveshaft ( try to move it up and down and side to side). most likely u-joint. driveshaft should be tight and not have any play where the U-joints connect. and the best thing is its easy to check! i'd check it and fix it before driving anymore as if its that bad where you have extreme vibration it will eventually break either leaving you stranded or causing a ▓▓▓▓load of damage.......

 

I ruled out my driveshaft by dropping and driving around in 4wd. I imagine you could do that on your truck too, right? Maybe you could pull it and then see if the noise is still there. If it's gone, then you know to replace the u-joints and you've already got the driveshaft out.

 

i second that,ill check the universall joints, get the ones that have a grease zerky on it ,so u can grease it up next time

 

If its gotten to that bad of a vibration then it will be very obvious if the u joint is bad. it will move all around and you probably will be able to see where it is broken or worn visually. no need to take it off unless you can see that its bad by moving it with your hand and inspecting it for breakage or wear to the u joint. mine did the same thing and once i got under the truck i could tell right away that the u-joint was toast. why do extra work?

 

ok some new signs...driving to and from work for the past two days i travel about 45-50 miles an hour...it gets up there fine and when i do get to that speed and i let off the gas completly the noise stops but if i so gently touch the gas pedal it makes the noise again...it almost sounds like a jake brake on a big rig...i let off the gas and the noise stops...hit the gas and it continues...vibrations are only at highway speeds...75 and up and u-joints are tight no play...any other ideas?

 

o and thanks for all the replies guys

 

I had trhe same thing on mine. I was told that when taking my foot off of the gass, there was no pull on the shaft, and that is why it didn't do it then. Again, I still think your U. Joints are your villen. Did you go under the rig like told to check?

Also, nine had no play in it at all untill I got the rig off the ground, then it had the play . It also moved up and down as well.

 

the symptons you describe were exactly what i experienced when my u-joints were bad. no throttle=smooth, on the pedal=vibration.

 

When mine did that I had to replace the front left half shaft.

 

I am having the exact same problems with 95 4runner..........I replaced the u-joints....didn't help any......I finally took it to a guy, and he says it's either a carrier bearing going bad, or the pinion bearing going bad.......I lost the pinion seal a month ago, so I figure the pinion bearing is toast...
He hasn't pulled the chunk yet to make sure,.....I'm looking for a chunk to replace it if it's the problem....

Either way it's $$$$$$

Chad