whitedevil

iTrader: (9)

I know a lot of ppl on the board have had the same issue that I had while using the poly trans mount, lots of vibes! Well, I finally fixed mine. I was getting vibrations so bad that I think it may have cause knock retard. I was under the impression that all LS1 F-Bodys came aluminum drive shafts, and for one reason or another, mine did not have one. I decided that it would be a good idea anyways, to go out and find one, so I did, installed it, and the vibes are allmost completely gone. I write this for the other ppl that are still plagued with the Tranny Mount Blues, If you are having vibes with an ES poly mount, take a llook at your DS, mine was out-o-wack, and now it is great.

camaroguy26

iTrader: (21)

good info. Glad you could finally fix it. I've been looking at these trans mounts but scared to get it for that sole purpose

gun5l1ng3r

My Al DS is a little scratched up. I wonder if that throws the balance off.

whitedevil

iTrader: (9)

I picked mine up with some scratches on it, but it still got rid of the vibrations. It is worth getting balanced, in all honesty, if you put in an ES mount, and like me, you had a steel DS, go get an aluminum one, try it.

Project GatTagO

iTrader: (7)

How do you know that your steel shaft was not out of balance? Your post suggests that an aluminum shaft is less likely to have a vibration. That is absolute BS. There are plenty of race cars (NASCAR for example) that run steel driveshafts and turn 10,000 RPM for 3 hours straight. You can bet they don't vibrate at all. At the same time, plenty of aluminum driveshafts have cause vibration due to being out of balance. On top of that your linking your motor mount theory to the driveshaft. Obviously those two things had nothing to do with eachother. Your cause and effect theory is a little flawed my friend.

Andrew

black00TA

iTrader: (3)

steel driveshafts ARE more prone to vibrations. thats why they were changed for the 98 model year.

but you are correct. both can vibrate just the same.

camaroguy26

iTrader: (21)

why wouldn't the DS be linked to the tranny vibrations? It's directly connected to the transmission, if one vibrates so will the other. The rubber mount just absorbed the vibrations more than the poly does. Maybe that's not the problem on every vehicle but on his it seems like that's the culprit.

Ferocity02

iTrader: (60)

Yes, it is clear your steal driveshaft was simply out of balance. The poly trans mount just made this unbalance more noticible to you. Balancing the driveshaft is definitly a start to reducing vibrations. Material has no affect on vibrations... to an extent. That's getting into metallurgy mumbojumbo.

whitedevil

iTrader: (9)

Totally agreed, The Steel DS was out of balance, It even looked like some one tried to balance it, and messed it up even more. Project GatTagO, I didnt suggest that just using a steel DS would make it vibrate, I am fully aware that "There are plenty of race cars (NASCAR for example) that run steel driveshafts" So you are not telling me anything I didnt allready know, ohh, and "plenty of aluminum driveshafts have cause vibration due to being out of balance" Did I say that an out-of-balance aluminum DS wouldnt make vibes?? Nope. I never linked "motor mounts" with "drive shaft" I linked "motor mounts" to "cause of vibration" lol. Here we go, "Your cause and effect theory is a little flawed my friend" Thats why taking out the unbalanced old DS and replacing it with a "balanced" DS eliminated the vibes? It didnt matter if it was steel or aluminum, the matter is, it being balanced, eliminated the vibrations.. camaroguy26, Ferocity02, you guys got the picture, lol.

Canuck

Where do you buy an aluminum drive shaft and how much?

Cap'n Pete

iTrader: (2)

It seems really common to get more vibrations inside the car with an ES poly mount, but a common "solution" to the problem seems to be installing the mount on its own, WITHOUT the steel plate that comes with it. Don't know if any of you have/haven't tried this yet, but try it and you might find the vibrations go away (or significantly reduce ).

SladeX

I run an ES poly mount with the numbs grinded down and no preload plate. You wouldn't know it was a poly mount until you shift hard from 3rd to 4th and it goes perfectly in... my stocker which had no tears in it did that to me on half the shifts into 4th when at WOT.

Your 4th gen should have an aluminum driveshaft stock if it was a 98+ car z28 with 3.23 gears + auto or 3.42 m6.

There have been cases of people selling cars with steel driveshafts because it's easy for a new buyer to overlook this.

NHRATA01

iTrader: (10)

That was a real mature response

Aluminum is less likely to have vibration than a steel shaft. It has a higher critical speed due to less weight, so it can rotate it faster before hitting its natural frequency which will cause noticeable vibrations. A steel shaft will require a much more precise zero balance than an aluminum one for a given speed. Hence the switch to aluminum for the non-speed limited cars after years of LT1 owners complaining about vibrations. And the GM factory is not all that precise compared to the attention given to a NASCAR part. Or maybe we should try spinning an LS1 to 9,000 rpms from the factory since, well, NASCAR does it too.

So your theory is also a little flawed my friend.