Vibration at 25mph

[sweetdiesel]

I need some opinions on what else to check?

my lly has a vibration that's starts at 18 mph worst is 25 mph and ends around 50mph

so far I've triple checked in neutral all ujoints
checked wheel bearings
had tires balanced and rotated
after rotating tires the vibration is still feeling like its in the rear ( feel it in the seat, not the steering wheel)
alingment is great


I thought maybe flex plate, but it idles great?

Thoughts?

 

[Chevy1925]

You popped the driveshaft and tried turning them by hand? Two peice or one peice?

 

[sweetdiesel]

2 piece and no


what's strange is the issue went away for about 1000 miles and then came back

 

[sweetdiesel]

James

do you need to remove the shaft or could I do that test in neutral?

 

[tinman22]

probably need to pull the shaft. those needle bearings might not show a problem while in place. one of my wheel bearings went bad and started making grinding sounds. but thought it was the front diff. had to take everything off including the brakes and rotor to find the problem. wheel wasnt loose or wobbly but once I could freely spin the hub I could feel and hear the problem.

 

[blk smoke lb7]

I had a similar issue after i reinstalled my trans after doing a new rear main seal but it went away after 3 or 4 test drives.Dont know what it was.

 

[Chevy1925]

James

do you need to remove the shaft or could I do that test in neutral?

I would pull it. I had one cap lock up and cause a sqeek/vib but you couldnt tell it was bad just by having the truck in neutral.

Also, are your yokes in phase? Or know what i mean by that?

 

[sweetdiesel]

I would pull it. I had one cap lock up and cause a sqeek/vib but you couldnt tell it was bad just by having the truck in neutral.

Also, are your yokes in phase? Or know what i mean by that?

ok, ill pull it and check! I really don't know what else would cause that? that's a good possibilty

Don't know why/ how it went away either??? no weather changes or truck changes?

I did notice my carrier is starting to go, but it aint bad.

 

[sweetdiesel]

I had a similar issue after i reinstalled my trans after doing a new rear main seal but it went away after 3 or 4 test drives.Dont know what it was.

I rebuilt this tranny close to 40k ago....aprreciate the input though

 

[sweetdiesel]

probably need to pull the shaft. those needle bearings might not show a problem while in place. one of my wheel bearings went bad and started making grinding sounds. but thought it was the front diff. had to take everything off including the brakes and rotor to find the problem. wheel wasnt loose or wobbly but once I could freely spin the hub I could feel and hear the problem.

hmmm

so jack the front and spin the wheel, wheel bearing feel good! but its been a while since I've changed one and being a lifted truck they tend to go sooner.

 

[sweetdiesel]

probably need to pull the shaft. those needle bearings might not show a problem while in place. one of my wheel bearings went bad and started making grinding sounds. but thought it was the front diff. had to take everything off including the brakes and rotor to find the problem. wheel wasnt loose or wobbly but once I could freely spin the hub I could feel and hear the problem.

I don't have any grinding noise while low speed driving....but???

 

[Chevy1925]

ok, ill pull it and check! I really don't know what else would cause that? that's a good possibilty

Don't know why/ how it went away either??? no weather changes or truck changes?

I did notice my carrier is starting to go, but it aint bad.

It wouldnt be the yokes then. Only thing else i could suggest is carrier bearing like you say.

No changes to the truck since this started?

 

[Mike L.]

If you can move the driveshaft up and down, your rubber support on the carrier bearing is bad. Very common.

 

[sweetdiesel]

If you can move the driveshaft up and down, your rubber support on the carrier bearing is bad. Very common.

Mike
its moves a bit, but I've had bad carrier bearings a lot worse and they don't make the truck vibrate like this?


Thanks for the input though!

 

[tinman22]

my wheel bearing actually made more noise the faster I went. i'm just using it as an example that a little wiggle test wont always show the problem. so a check while installed may not show the problem either. good luck in your search

 

[sweetdiesel]

If you can move the driveshaft up and down, your rubber support on the carrier bearing is bad. Very common.

Even more common on lifted trucks that see a lot of offroad!

 

[sweetdiesel]

my wheel bearing actually made more noise the faster I went. i'm just using it as an example that a little wiggle test wont always show the problem. so a check while installed may not show the problem either. good luck in your search

What kind of noise? I've noticed a lil more whistle....but this truck has always been loud! lifted, big tires, strait piped and just old! lol

 

[tinman22]

hmmm metal on metal rubbing. kind of a hum. I actually thought it was my tires that were whooped and worn unevenly.... till I changed the tires and it was still there. then I thought I had a bad bearing in the front diff. or loss of oil in there. but level was good. checked wheel bearings for wobble with tires on and they were still tight. when I pulled the wheels and brakes and spun the hub I could hear a faint squeek and feel the crunchiness of the bearing

 

[Kartmnn]

I have the same vib. on a two wheel drive reg cab long bed truck. 25-30 mph everytime with new tires and carrier. Everything feels tight! Leaving for Cali next monday. HELP!

 

[LBZ]

Probly your steady bearing and rubber insulator for it Slim.
It does have 200 000 hard miles on it.