BLK,97,T/A,M-6

I put poly motor mounts on my car and noticed a LOT more vibration, especialy above 3k rpm's. I was wondering if this is normal, orif I have an imbalance issue with the new flywheel I got from Autozone. Any opinions are appreciated.

SS MPSTR

iTrader: (1)

New one's in my car certainly increased vibrations through my k-member.

ABA383

iTrader: (1)

Mine increased vibration slightly, but it wasnt that noticable..Then again Im running rod ended suspension stuff, too so im used to all kinds of noise...

--Alan

hyperzone

I switched to a whole new motor and to a UMA K-member when I put in my polys soooo.... its hard to tell what did it. I do notice a little more vibration but, nothing real bad. Its felt more at idle than higher RPM. I have a dumped 3" exhaust and loud stereo so, I'm used to lots of noises as well so maybe I just dont notice it much.

I always thought most motors should smooth out as they rev higher... Are you saying that yours vibrates while driving and sitting still at high RPM or just while moving? If only while moving, it might be the driveshaft or U-joints. Just another thought.

SS MPSTR

iTrader: (1)

well stated - my situation exactly. at higher RPM, the rear of the car is all over the place, so it's hard to tell if there is more vibration then

leadfoot4

iTrader: (1)

3K RPMs while "blipping" the throttle while sitting, or 3K RPM while driving/accelerating?

I put both the poly engine mounts as well as the tranny mount and did have some vibration, while driving. However, the new mounts changed the way the engine/tranny sat in the chassis, just a little, but enough to change the pinion angle. Once I readjusted the torque arm, the vibration went away.

If the vibration is significant, I'd be thinking flywheel....

BLK,97,T/A,M-6

I can put the e-brake on, put the car in 1st, with the clutch in an once I rev it up it vibrates. Bad enough that I don't want to beat on my car( which is why I bought it). So it's not the drivetrain.

Purple95Z28

iTrader: (6)

Wow does that suck... I don't think it's your motor mounts, I have them in my car with a cam and it's a little "rougher" then the stock mounts but it still feels smooth at revs

BLK,97,T/A,M-6

the problem is I did a bunch of stuff all at once ( motor mounts, clutch+pp, flywheel, lt's,ory, slp lm, ls1 ds, and universals). So it's hard to track down the problem.

Purple95Z28

iTrader: (6)

Are you sure the headers aren't touching the floor when you rev it a bit? It shouldn't if you have fresh MMs, but you never know.

DAVE00

iTrader: (10)

Did you put a new pilot bearing in when you did the clutch and flywheel swap, as this vibration could be caused by that?

BLK,97,T/A,M-6

I don't think so, there are no scratches in the collectors. I think it's the Autozone fw. I will be pissed if it's bad. Better believe I will let them hear about it. The question is where do I get a good fw for cheap?

LTBANDIT

iTrader: (3)

me, and alignment was a bitch... and i did notice some vibration but it seemed to calm down after some time...

BLK,97,T/A,M-6

no, but I will if I have to tear the car down again!

hyperzone

I would recommend the spec billet steel flywheel. It is a little heavier than stock and balanced well. Not cheap though... Dont know where you will find a "CHEAP" NEW flywheel that is decent.

leadfoot4

iTrader: (1)

I agree!

Not to be sarcastic, but it sounds like you might have gotten a "cheap" flywheel already. Now you need a "good" one.

LS1 SPEED

iTrader: (22)

I do agree with the above. We have used them in both LS and LT based vehicles with no issues.

if you need a flywheel shoot our sales guys a call

I do believe you have more of an issue then the Poly mounts. They do increase some vibration over stock rubber, but nothing that should be a concern as you have noted.

good luck sorting it out