having a slight issue....feels almost exactly like an out of balance tire...
rhythmic vibration.

ONLY when full throttle though....
starts at about 3500ish... and ever so slightly gets worse as the rpms go up.
so far it seems notably worse in 3rd, but is there faintly in second....and i can feel it a bit in fourth, though im not flooring it to that rpm in fourth for obvious reasons.

i feel it at 4000 in say 3rd....but if i go to 4th and cruise at the same speed, its not there....so that kinda rules out balance right?

the last few days are the first time ive really put my foot in the car at all over the entire winter....
and since the last time i opened it up...ive changed quite a bit.

zzp header/dp, engine/tranny mounts, S2 axles.

is it possible for an exhaust leak to vibrate through my mounts and cause something like this? (i have a leak atm)



so throw some suggestions at me

Im avoiding the thought that these axles are fubar :/ as I bought them used (though barely used) and i havent really even used them yet.

 

Something with rotational force causing it. Its not a mis weighted wheel, because that would only happen in certain MPH ranges. Something is very wrong.

Is there any kind of wheel movement?


EDIT: I feel like an idiot. Its the mounts causing the said new found vibrations. I'm almost confident in that.

 

go out and get the car where it vibrates, then put it in neutral.

its not a tire/wheel concern. if you're doing say 65 in 3rd and feel it, but you dont feel it in another gear at the same speed, probably not tires. its probably not axles either. or an exhaust leak.


wheres the vibration seem to come from? front or rear? where do you feel it at?

 

arent you on winter tires still ?

 

yeah,

the vibration does not affect the steering wheel side to side, but i feel it most through the steering wheel, it feels like its coming from the drivers side.
like i said, its only when applying alot of torque, doesnt do it at all at any cruising speed.

another thing.....today the dealer changed the drivers side axle seal for me, and i cant be sure, but i never really felt it until today....
but then i havent really opened it up alot until today either

surely they arent stupid enough to screw an axle seal install up :/

 

Its the mounts. Poly or solid mounts will induce vibrations that your not use too.

 

yea the deal with it occurring in some gears but not others leads me to believe that something is hitting its resonance frequency. So something could be shaking because of a certain frequency of your exhaust at random rpms in different gears. idk if thats the sort of shaking your describing though

 

the best way to describe it, is it feels exactly like an out of balance tire.

 

try swapping the one axle to eliminate the possibility before it goes in for the seal.

 

it went in for the seal today......

dun du dun dun.....

yeah...exactly what im thinking.

already called sean as soon as i felt it to make him aware.

 

i would check and make sure the axle is actually all the way in the trans. make sure the nut is tightened on the knuckle. make sure your lug nuts are tight. ect. could be nothing or could be something bad. did they do anything else to your car besides the seal?

 

nope just the seal

 

bro, you're describing EXACTLY what i went through when i got the car in that first post... def. sounds like either a bad axle or cv joint.

 

:/ im scared thats what it is

Ive only had these axles on barely 2 weeks, and the most launching ive done is on winter tires in ugly weather.
they havent even worked hard.

 

did you put them in, or did someone else? maybe they weren't installed properly? i hope it's not a bad axle, that would suck, they're new and i know they're not cheap even though you got them used (i think)

 

maybe just because they are a more heavy duty CV joint

 

my dss axles seemed to vibrate and those the mounts don't help any

 

o rly!!

so you had a bit of a shudder in 3rd?

do tell, this one has me stumped.

yeah used, but barely.
they might as well be new axles.

it seems such a strange problem to only happen at such a specific set of circumstances.

Ok, so basically, after a bit more playing, and talkin it out with firestorm ive figured a few things out.

it seems to be happening at a certain speed, regardless of gear...
but only under load.

Considering there hasnt been this issue previously, and it feels like its coming from the drivers side, and my dealership just happened to change my drivers side axle seal for me today....it just seems to coincidental.


so....did the dealership tweak my alignment/toe during the axle removal?

heres the theory in my mind....

FWD have a bit of toe out....like this \ /

this is because when accelerating, the alignment will tend to straighten out. (rwds are the opposite)

so my thinking....is the drivers side is not quite at that right angle.....
during normal driving, its not affecting anything...
but under load, its not coming back even, and is causing this shudder....



Anyone care to shoot holes in it for me?
ideas? thoughts?

at this point ill be calling the dealer in the morning to come for a drive with me and see the issue.

 

i think with a well executed labodomy, it wont matter to you anymore.......and dawife can get more cats.

 

well im getting the sinking feeling one of my S2 axles that have been in for 2 weeks, and havent even seen a hard launch, is toast.

can anyone with S2 axles, or axle knowledge chime in here....

it seems that when you give a pull on the transmission shaft, and the middle shaft, the joint kinda "separates" and seems to almost stay locked out of joint....but if you just twist it and jiggle it is slips right back into place.

is this normal?

 

Hey an0malous, did you get this problem resolved? My car is going into the dealer tomorrow morning for the exact same symptoms. From what I can tell it's the axles. I was curious what the resolution was in your case.

Thanks

 

it was a bad axle, freshly humped by a sad GM tech.
all better now.