shimy?

[super_stroke]

my truck, around 40-50 mph, has a really anoyying shimy i guess you could call it. it feels like the back of the truck is moving up and down really harsh. shakes every thing in the cab. almost like a tire thats not balanced. yes, thier balanced, internal with beads. it does it when braking and acclerating. could it be a u-joint? i checked them and all were tight and not worn. could a warped rear rotor cause this. that would explain it on braking but not on accel. ideas?

[mschn99]

can you "drive through" it...meaning go faster and it goes away.....and also, is there any noise associated with it??

[super_stroke]

yeah it goes away. it dont do it from 0-38ish then around 40 it starts and stops around 50ish. no noise either.

[mschn99]

Originally Posted by super_stroke

yeah it goes away. it dont do it from 0-38ish then around 40 it starts and stops around 50ish. no noise either.

sounds to me like you threw a wheel weight.........i would have those tires checked.....the only vibration you can really "drive through" is usually a tire......a u joint should have a noticable growl and a rotor has to be EXTEMELY warped to have any vibration with the brakes not applied......also...just to be really safe.....make sure your lugnuts are tight..........Marc

[super_stroke]

my wheel weights are inside. they have balancing beads in them. the tire shop said they were to big to put on thier machine so they put beads in em. i went back to them right after i got them because a some thing similar and they said to give the beads time to "find thier spot".no problem after about 100 miles it gradualy went away. i'll check the lugs though.

[mschn99]

Originally Posted by super_stroke

my wheel weights are inside. they have balancing beads in them. the tire shop said they were to big to put on thier machine so they put beads in em. i went back to them right after i got them because a some thing similar and they said to give the beads time to "find thier spot".no problem after about 100 miles it gradualy went away. i'll check the lugs though.

i dont trust those internal beads....i would put your rear tires on the front...and the fronts on the rear and see if it changes.......another trick on bigger tires, since their balance point changes more with wear, is to put "slime" in them......the slime, as long as its driven daily......will coat the wall and kinda "self balance" the tire.......just a thought.......Marc

[super_stroke]

you know, its about time for a rotate,oil change, coolant flush,hose's, t-stat, and belt. hopin it'll be warm for good soon.yesterday it was 60* now its 30 somthing.

[99Smokin73Stroker]

I bought my 35" nittos from discount tire and they've never had a problem getting them balanced. Now Tire Barn for that matter couldn't balance a book on their desktops....I had to go back several times before they finally got my old 33" bfg's right on my old truck..

[Lone Ranger]

Hello from Oz (Australia)
I have a slight "shimmy" in mine under load about the same speed and it is not tyres... In my Crew Cab 2003 7.3 PSD, there is a carrier bearing mid way down the rear tail shaft (drive line to you blokes).... Anyways we might have a slight language barrier here, but mine has a power on shimmy as well. The carrier bearing is in a rubber honeycomb, and with 70,000 kms on the clock it must be weakening a little... Hense power on, slight shimmy from the rear. This could be what you are experiencing,, Only a try.. Regards from Oz,
da Lone Ranger

[Banshee34]

Similar problem here....

Mine doesn't seem to like between 40-45 on the speedo (which is off, so lord knows what the speed is precisely).... and it's not my tires.... To me it almost seems like the engine is running rough, but it does vibrate the whole truck.

Very interested in what you find out Super Stroke!