IdriveaV

iTrader: (5)

So it started last week out of no where.
If i start driving there are no out of the norm vibrations, until i hit 35-40 then the car starts to vibrate, the higher the speed the worse it gets. Doesnt matter what gear 1-6 once it hits 35-40 it starts to vibrate, if im going 35+ and not in gear it has no vibrations, if im going 35+ and in gear and not giving it throttle it doesnt vibrate, but once i give it throttle it starts to. If i put in 6th gear and give it half throttle it feels like the cars gonna fall apart.

Took a quick look at it the other night was dark and wet out didnt have much time, but everything looked ok from what i could see.

I will be putting it on a lift tomorrow to look into it a little more, was just hoping to get a little input on opinions of the cause.

Nothing has been done to the car recently that might have influenced this.

I have corsa exhaust and i read that it might hit the driveshaft sometimes so thats something im going to look at also, even tho it doesnt make sense that it only happens under acceleration at 35+

Any feedback would be appreciated.
Thanks.

punishmentcycle

iTrader: (6)

lookslike u have all the mounts and stuff done so id look at the driveshaft cv's and carrier bearing first..then look at the mounts for loose bolts or failed mounts.. make sure the trailing arm bushings didnt back out and all that.. seems weird for a stock rearend to vibrate but its not unheard of

isis

iTrader: (1)

I'd eyeball every mount first. Push/pry with prybar and see that it's all tight. See how much play the rear has by wiggling the driveshaft (trans in neutral) with the Ebrake holding the rear wheels from spinning.

BudRacing

iTrader: (3)

My guess would be an extra saggy carrier bearing, but I've been wrong before.

Skidmarcx

I suspect driveshaft or half shaft

07CTS-V

iTrader: (6)

Are you still running the stock dual mass flywheel?

isis

iTrader: (1)

Check Flex couplers too.

IdriveaV

iTrader: (5)

To my knowledge the previous owner had the clutch replaced, not sure if he upgraded or not.
So most likely still dual mass.

I dont have the rear bushing installed, its in the diff sitting in my garage, i was gonna do g force axleshafts and install this new diff within the next month.

Now im concerned if it is a cv if anyone sells complete axles for less then 1500+
so that i can just slap them on and not have to rebuild/replace the cv's and buy the shafts.

I was thinking maybe it is the carrier bearing.
If so im assuming its better to just go to a one-piece driveshaft?

kl2onik

iTrader: (3)

Can be many things man...the dual mass will cause it to vibrate some in higher gears just not as violent as you describe. I had a similar scenario...come to find out one of the bolts holding my shock to the lower control arm was missing. Must have flown off somewhere, I also got violent vibrations especially on bumps. Also check to see that none of the weights they use to balance your wheels have flown off or something. Could just be a simple balance issue. Ive noticed most of the stuff that happens with me is simple, yet I go digging through assuming more serious **** every time. Good luck and please share what it was when you find out man.

IdriveaV

iTrader: (5)

Well i was ruling the wheels out cause it only does it when under acceleration and above 35 MPH.

But Im hoping tomorrow when i get it on a lift its something i can spot easy and get it taken care off.

heavymetals

iTrader: (3)

Sounds like the imbalance is between the output of the transmission and the diff under torque.

"Doughnut" coupling or driveshaft IMO.

DMM

^ This. Driveline vibrations that are speed related are 99.9 out of 100 times propeller shaft related. If the flywheel or balancer were bad it would be more RPM/Load related than speed related.

My guess would be the driveshaft as well...two piece shafts are known to have particularly violent vibrations when out of balance.

IdriveaV

iTrader: (5)

Anyone know if the CTS Base driveshaft is the same?
Anyone have a driveshaft up for sale?

Cadzilla

iTrader: (3)

my guess is that piece of sh7t flywheel. do you get the same vibes in neutral at the same rpms?

Bacon

No, the base CTS model is not the same.

kl2onik

iTrader: (3)

Hey I'm also dealing with some vibration bs issues but its too cold to deal with them at this point. Have been making a list on what to check when I can actually get under there to look at it. Also drove by lyndsay caddi yesterday and noticed an employee v1 parked there, maybe will have him look at it and see what he thinks it could be. It seems that most places/shops I go don't know much more than I do about this car ( which basically is nothing). My vibration is at higher speed as well and I seem to get it engaged or in neutral about the same. However, if I punch it at higher speed it seems like it becomes less of a vibration, but that may just be the torque messing with my head. Regardless, I was doing some reading on here and this thread was pretty helpful so check it out https://ls1tech.com/forums/cadillac-...7-cts-v-4.html

Things to check:
balance
flywheel
mounts
driveshaft
cv's
flex coupler
and the list goes on...

IdriveaV

iTrader: (5)

No vibes if not accelerating or if its out of gear.
Only vibes at 35+ when giving throttle.
One of the mechanics at the shop i know is looking at it today.
He said it seems like a driveshaft issue

07CTS-V

iTrader: (6)

The dumbass dealer left my driveshaft bolts at the rear CV loose and it did this. Ended up ruining the CV after all the grease slung out.

adanieljohnson1

iTrader: (1)

Sounds like you just need the tires balanced to me... Same thing happens to my wives SUV at 60mph when she needs a Balance

IdriveaV

iTrader: (5)

Unlikely considering it only happens when giving throttle.
If it was consistant ingear/outgear/accelerating id agree