Theking

iTrader: (1)

Hi!

Well I have a strange vibration on my hand,
it have come and gone during the last year.

The car starts to vibrate (I feel it in the seat and not the steering wheel).
I have tested with a friends wheels (he have the same modell and all and no vibrations on his car) with his tires (bak ones) the vibrations got better but not good.

I also changed Transmission mount and torquearm bushing to Energy Suspension also I replaced the engine mounts and it also helped to make it better. But not good.

The vibrations comes around ~70mph and if I drive 75mph there is no vibration.

and around ~85+ mph it comes back and it feels more then. if I slow down it gets better and better until it dissapears, if I floor it again and move up in speed the vibrations comes back.

I have tried D and [D] and the vibrations seems to be speed relevant (its hard to tell if its RPM or SPEED that changes the vibrations)

I also replaced the U-Joints 1½ years ago , there was a shop that made the change (and they didnt balance it, is it needed ?) and they also changed transmission fluid and filter (all looked very good inside) they also replaced the rear axle fluid at the same time al looked really good.

So any input on the vibrations problem ? could it be that the propeller shaft is 180 deg wrong ? or ?

Please help me track it down.

midnightfirews6

iTrader: (1)

Could be the driveshaft. Steel driveshafts are famous for causing vibrations, switching to an aluminum one is said to relieve this and will slightly improve gas mileage and acceleration.

19Camaro89

and when you get a chance go out and lift the car up then see if you notice weight's missing in the flexplate and then check the end play at the crank shaft move it in and out of course with the engine off and cool and while your at it check the harmonic balancer for play! if you have play you found your problem..... and theirs nothing you can do about it till your next rebuild, if you notice movement in the harmonic replace it weights missing replace it with new parts of course!

Theking

iTrader: (1)

Thanks, but can the driveshaft go bad for nothing ? the vibrations have come "recently" I owned this car for 7½years and it wasnt this when i bought it.

I will check the driveshaft for vibrations etc, and also check to see if the harmonic balanser is working as it should and also check for play in it (but last time I checked it was fine, flexplate looked really good to when i changed starter, but ill recheck to just to be 100% sure

So you think an alu driveshaft will solve this problem ?

anthony714

iTrader: (5)

update?

Theking

iTrader: (1)

Yeah, but I havent tested so many things yet, working pretty much everyday so theres not much time atm to be in my garage.

The thing I tested was that I borrowed 2 backtires from a friend that also have a camaro, with his backtires the vibrations got much better, but not good or gone.

So I need to balance my 4 tires as a start.. and then keep searching for the cause..

Tash3r

hey man I was having this same problem, when I went to get my new tires they also fixed the idler arm. It no longer has the shaking problem, just my 2 cents.

Theking

iTrader: (1)

idler arm ? my brain isnt connecting right now, what part is that ?


EDIT: google is a friend, well I have no vibrations in the steering wheel so it couldnt be the idler arm then right ? the vibrations seems to come from the back/under the car and if im at ~1500rpm the car shakes alot, and if I downshift and keep the same speed the vibrations changes (and sometimes dissapears) and if I floor the pedal theres no vibrations.. its only around 1500rpm (and some right below 3000rpm...) strange..

partimechanic

Isolation of the problem(s) described here will help.

Is the vibration speed (MPH) related or RPM related? With the vehicle in neutral and at a stand still if you hold the RPM @ 1500 does it vibrate? Then it would be engine related. (harmonic balancer, flywheel, missfire....)

If it vibrates when only moving down the road then you are right to go after tires, (look at your wear patterns also) drive shaft, etc.

kit-ss

iTrader: (1)

Definately driveshaft. Long story short. I had the same exact vibe issue as you. First balanced the d shaft. Shop said it was good. Well I replaced a lot of parts and no luck. Even the rearend with a different ratio. Still had the vibe only it was at a higher speed which made me happy for a while til I did another search for answers and someone said driveshaft wheres out and cannot be balanced. $100 Aluminum shaft cured me. Drive line shops do not spin the shaft high enough to make the vibe appear so they say its fine. Just buy the damn shaft before you blow a bunch of money and time on other things like I did. If its not the shaft you can sell it or keep it. Great upgrade anyway.

squatingeagle

i have the vibration at 70 and everything past. ive replaced drive shaft, u joints, axle shafts and tires. i dont have bent rims. gm service manual says rough rear wheel bearing. im going to run the car without axle shafts today and see if it goes away. if it doesnt vibrate with the axles out, bad bearings.

squatingeagle

another way to check if bearings are bad is to grab your rotor top and bottom and try to pry/pull in and out. you should get NO play. if any your bearings are worn out.

anthony714

iTrader: (5)

lmk asap what you find.mine isnt bearings. i know theyre new and if i go 70+.pop her einto neutral and engine rpms go down but speed stays the vib goes away ,thus eliminating bearings(hopefully). im hoping by some fluke and having a custom exhaust that it is just exhaust pulses/harmonics creating the vib. some cars have resonators and weights on exhaust to combat this condition. either way lmk asap.

squatingeagle

finished up a few hours ago rides like a dream now. except that its 20 years old with 170xxx on it. bearings did the trick sure enough got one out and it had a bent cage. anthony714 if you hit neutral and the vibe goes away it isnt rear bearings. check engine/tranny mounts if its RPM related

anthony714

iTrader: (5)

thanks. my mounts are fine. they were new poly mounts. i went to a rubber tranny mount,no effect. too lazy to swap out motor mounts but i dont feel its neccessary. this blows.im selling the car. geting too old to be playing wrench. any one want a car? damn near mint.if you find traction it will run 11's on all motor

Red92Bird

Have you recently lowered the car? If so it could be your pinion angle. I noticed after lowering my car two inches along with adding the poly trans mount it caused some vibes around 70. An aluminum driveshaft helped some but I need adjustable control arms and torque ARM to solve the issue completely.

fireburdluvr85

what about sagging springs? in effect that would "lower" the rear changing the pinion angle?

syc0path

I have the same problem (so have many others) and I've been thru a lot of the same fixes. At this point, the vibration is still there but not really objectionable anymore.

Here is a very long and very detailed thread about it: https://www.thirdgen.org/forums/tran...bration-3.html