Lawnboy

iTrader: (54)

Energy Suspension tranny mount? getting a rattle noise at 3,000 + RPM

Car is a 01 SS M-6, not sure what it is, but it sounds like a rattle that comes on and gets louder at 3,000 rpm.

we just installed a new LS6 with poly motor mounts and a Energy Suspension tranny mount.

Rev limmiter is set to only 4,000 for me to break in the new motor.

ok it sounds like its comming from the center dash area , (radio area) and maybe the center console area,

I was told to see if the noise/vibration is heard with the car in park and rev motor to 3,000, i did that no noise,

and also with my foot on the clutch and car in gear at a stop , No noise.

so it only makes the noise while in motion, driving.

so i guess its not the new motor,

and it didnt do it a month ago, car now has 1,500 miles on the new motor and started doing it 2-3 weeks ago at about 1,200 miles ,

I also installed a spec stage 3+ clutch with the new motor that was fully ballance with a new stock fly wheel

do Energy Suspension tranny mounts cause a vibration and something to rattel in the car due to the mount being made of a harder material?

the rattle sounds like a new PCV valve being shaken back and forth realy fast , very weird, i hop nothing serious is wrong.

Please help,

VoggsStage1

Well with new poly mounts you could be getting alot more NVH from motor/trans now (noise, vibration, harshness) could be dash rattles, exhaust, or otherwise.

Lawnboy

iTrader: (54)

i hope thats all it is, but it didnt make this noise at first , i been breaking in the new motor over the last 2.5 months and it started a little about 3 weeks ago , seems this past weekend when i last drove the car , that it got louder , maybe that it got a little colder out?, the tranny and motor mounts are harder than rubber , maybe in the cold its not taking up the vibration, still weird to me.

99Bluz28

iTrader: (35)

If you grind the preload bumps off the ES trans mount that should help.

VoggsStage1

Also check exhaust manifolds studs/nuts, after install and break in things have away of loosening up or backing off.

VoggsStage1

I recently had a severe screeching noise when down shifting and decelerating, turns out it was the headers loosing up against head and rubbing.

Lawnboy

iTrader: (54)

If you grind the preload bumps off the ES trans mount that should help.


what are these??? i dint install the tranny mount, someone else did

99Bluz28

iTrader: (35)

Look at the cutaway picture on the right

http://performanceparts.com/performa...on_3.1108G.jpg

Lawnboy

iTrader: (54)

ok by grinding them off what will that do ??? do i grind the bottom plate off to?

99Bluz28

iTrader: (35)

By grinding them off the mount won't be nearly as stiff.

No,all you want to do is grind the 2 preload bumps down just enough so the preload plate doesn't compress the urethane on the mount at all.

Sprayed 99

iTrader: (14)

i had the same problem when i switched to that poly trans mount. the problem is that tranny mount is taller then the stocker and when its bolted up in place it moves the back of the trans higher. easy fix for this is to shim the trans x-member lower to put the back of trans down where it belongs. you need to put your shims between the body and the tranny x-member.


i used 3/8 thick flat steel and seemed to work fine. i just took the x-member out, traced the ends where it bolted to the body, cut it out on the 3/8 steel, drilled my holes and installed. problem solved.


hope this helps

Lawnboy

iTrader: (54)

might as well just put a new stock mount back in,

F-BodyMind

iTrader: (12)

Go back to stock rubber, no vibrations.. You might have to replace it tho in the next year or so.. I think its worth it for a smooth confortable ride.

Lawnboy

iTrader: (54)

thats what i am saying, this vibration and noise **** ant worth it,
I have New poly motor mounts too, they seem to be fine, and motor sits rock steady at idel although i dont have a big can (215-230, .574/.601 lift on a 116) blower cam

i think its that ES poly tranny mount causing it

Grn4fbody

iTrader: (2)

Its normal with a harder mount like that, with my poly mount my shifter vibrates more than a lawn mower powered *****.

Lawnboy

iTrader: (54)

its not so much the vibration its that dam PCV valve rattle sound, comming from the console and dash, has to be that dam mount

99Bluz28

iTrader: (35)

When I first put my ES trans mount on the vibration was really bad, so I took it off and put the stock mount back on. Then probably 1-2 months later I came across a thread about grinding the pre-load bumps down. The very next day I re-installed my modified ES trans mount and been happy with it ever since; that was over 6yrs ago.

F-BodyMind

iTrader: (12)

Hey bluz28 you got the link to that thread?..

99Bluz28

iTrader: (35)

It's really, really simple, just go back over what I posted.

Lawnboy

iTrader: (54)

OK by grinding down the pre-load bumps, what is this doing??? what are the pre-load bumps for , and why are they causing the vibration?


Do i need a ES poly tranny mount over a new stock one, what benifete do you get with the poly mount over the stocker?

thank you all , for your help