Poly Tranny Mount Question...
05-29-2009, 12:24 AM
#1
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Poly Tranny Mount Question... Made a few mods to the SS today...one was a Polyurethane Tranny Mount...Before install, smooth, clean running car...after install, mild vibration feels ALOT like unbalanced driveshaft...was perfect before...is that just because I can feel vibrations more with a poly mount than a rubber??? If so is that what it feels like is DS Vibration???
05-29-2009, 02:13 AM
#2
Hey:
I worked with an offroad race shop and most all of the guys there used poly mounts, and they have enough vibration to deal with already, they don't go looking to add more. But I know they made them buzz more.
Also do you have poly or solid motor mounts? Also I am not positive but I think Energy Suspension had some kind of bulletin out on this. About not to use them without the plate or something. This was a while back
What brand and pn# did you use?
Did you use it with the top plate?
Dub
When In Doubt Do Without
I worked with an offroad race shop and most all of the guys there used poly mounts, and they have enough vibration to deal with already, they don't go looking to add more. But I know they made them buzz more.
Also do you have poly or solid motor mounts? Also I am not positive but I think Energy Suspension had some kind of bulletin out on this. About not to use them without the plate or something. This was a while back
What brand and pn# did you use?
Did you use it with the top plate?
Dub
When In Doubt Do Without
05-29-2009, 06:04 AM
#3
The poly mount isn't as "squishy" as the OE rubber mount, so you'll feel a little more vibration.
There have been several discussions on this forum about the poly tranny mounts. The consensus is to NOT use the "pre load" plate, and sand down the "humps" on the mount as well.
I have both the poly engine mount cushions as well as the "modified" poly tranny mount. Yes, there's a little more vibration transmitted due to the harder durometer of the poly, but it's not a Cadillac, it's a performance car....
There have been several discussions on this forum about the poly tranny mounts. The consensus is to NOT use the "pre load" plate, and sand down the "humps" on the mount as well.
I have both the poly engine mount cushions as well as the "modified" poly tranny mount. Yes, there's a little more vibration transmitted due to the harder durometer of the poly, but it's not a Cadillac, it's a performance car....
05-29-2009, 06:23 AM
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Next to the long tubes and poly motor mounts, I doubt I would even notice vibration from a poly trans mount. It is normal...I had one on my '94 T/A and it did the same thing. I concur with leaving the plate out if you want less vibration...though I don't think it is that bad...especially enough to warrant pulling it back out and removing.
05-29-2009, 12:31 PM
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I wasnt going to remove it, and I'm not "complaining" about the vibration, I just wanted to make sure that the vibration was from installing the mount and not because the DS was off balance...As long as I know its the tranny mount I am fine with it cause its not THAT bad, but if it was my DS off balance that could cause drivetrain issues which I don't need. I used the Energy Suspension Poly mount with the plate, I may take it out late on, I dunno...we will see how things go
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05-29-2009, 02:30 PM
#8
05-29-2009, 02:32 PM
#9
Hey:
I want to know how you got it back on with the plate, as I didn't think it would go on without the mods (leave plate off, grind/sand down humps) as it was too thick.
I don't want to be an alarmist here, but Please go back and check on this as the mount won't tighten down unless you used some spacers on the tranny cross member. Not a good thing to damage your car for a poor fitting $20.00 mount.
I don't think it will squish enough without binding when you use the plate.
If the tranny cross mount is not tight to the body it will vibrate really bad till the bolts back out, and cause real problems for you, like maybe broken drive shaft. Without a DS loop you may be trying out for the Fbod pole vault olympics.
But if you didn't use the plate and did shape to fit, then ignore most of above
I went for a ride today in my car that has all poly mounts and its a buzz feeling not a shake vibration. it makes so many noises that I've gotten use to it all.
Also blue loctite the 4 tranny cross mount bolts if you haven't already.
Dub
When In Doubt Do Without
I want to know how you got it back on with the plate, as I didn't think it would go on without the mods (leave plate off, grind/sand down humps) as it was too thick.
I don't want to be an alarmist here, but Please go back and check on this as the mount won't tighten down unless you used some spacers on the tranny cross member. Not a good thing to damage your car for a poor fitting $20.00 mount.
I don't think it will squish enough without binding when you use the plate.
If the tranny cross mount is not tight to the body it will vibrate really bad till the bolts back out, and cause real problems for you, like maybe broken drive shaft. Without a DS loop you may be trying out for the Fbod pole vault olympics.
But if you didn't use the plate and did shape to fit, then ignore most of above
I went for a ride today in my car that has all poly mounts and its a buzz feeling not a shake vibration. it makes so many noises that I've gotten use to it all.
Also blue loctite the 4 tranny cross mount bolts if you haven't already.
Dub
When In Doubt Do Without
05-29-2009, 02:37 PM
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does your car vibrate at all times or only sometimes? my car vibrates only after is shifts into second. don't know if its the poly mount or not. the vibration is annoying and not something I would want to continue to live with as it feels like im going over those small bumps they put by the shoulder and toll plazas.
Last edited by C_Rules; 05-29-2009 at 02:45 PM.
05-29-2009, 05:13 PM
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If you are making any kind of power and have a shift kit or your auto. shifts hard due to the upgraded line pressure (corvette servo), you can snap a brand new OEM rubber mount pretty easy. I replaced my old one with a stock one and within 5 runs popped it too...never had another issue with the poly mount on that particular car. I still have to put the poly mount in my current car...still stock for now...but I have yet to run it at the track since I got it. First couple runs ought to snap her and force the issue :-p
05-29-2009, 05:37 PM
#17
sorry I have to disagree with that.
I have seen them break on mild running cars even up here where we make now power.
and that's on the street, not dead hooking on the track.
If I need a driveshaft I will have one built or have mine balanced, but I will NOT be using an alum anytime soon. Well at least an ls1 aluminum
I have seen them break on mild running cars even up here where we make now power.
and that's on the street, not dead hooking on the track.
If I need a driveshaft I will have one built or have mine balanced, but I will NOT be using an alum anytime soon. Well at least an ls1 aluminum
05-29-2009, 05:48 PM
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If you are making any kind of power and have a shift kit or your auto. shifts hard due to the upgraded line pressure (corvette servo), you can snap a brand new OEM rubber mount pretty easy. I replaced my old one with a stock one and within 5 runs popped it too...never had another issue with the poly mount on that particular car. I still have to put the poly mount in my current car...still stock for now...but I have yet to run it at the track since I got it. First couple runs ought to snap her and force the issue :-p
05-29-2009, 05:57 PM
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Installed a poly mount today on a ls1 a4 and i could feel it vibrate more and it also make it where you can hear more tranny and drivetrain noise. This was a prothane mount.
Last edited by 1eyedmaro; 05-29-2009 at 06:05 PM.