Ok, I just replaced my second trans mount in about a year. Tore through each rubber factory style mount I put in, so this time I put in the Energy Suspension poly mount.

Now since I did this switch, any time I'm under load at around 2k rpm or so, the whole rear end vibrates really bad. I'm starting to think that maybe this was the problem that kept tearing up my old mounts and I never noticed it because the rubber mount absorbed all this?

Anyone have any ideas what might be causing this? It's rather bad and I'm worried about tearing up something else now.

(Stock 305 with auto trans.)

Carl


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GndPrx
http://www.caraudioresources.net

 

I'm hoping somebody can address this! I just purchased an '87 with a broken mount 5 days ago... I replaced the transmission mount with the Energy Suspension piece - and now the car vibrates pretty badly at 40+ MPH.... I was thinking I aligned it incorrectly - but there isn't any adjustment - is there? 3 bolts out... 3 bolts in... Hmmmm.....

Also, while I was at it - I bought the secondary crossmember mounts.... BUT.... Where the heck do they go?!?! I have no idea.. Stop laughing... It's not funny...

Anyway - what the heck did I (we?) do to cause the vibration???

Thanks very much!!!

 

I'm kinda glad to see that I'm not the only one (no offense) that sees this problem with that particular mount in there.

Hopefully that means that someone else will have dealt with and probably fixed it and may be able to help.

Thanks,

Carl


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GndPrx
http://www.caraudioresources.net

 

I've got the same problem with my car - and the same Energy Susp. bushing. I don't know what the cause is, but my vibration starts at 65 mph and by 80 its horrible. I'm going to have my drive shaft balanced. I just replaced the U joints. Those are my only ideas.

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'83 Trans Am. 400 CID, 224/234 crane cam, Summit aluminum roller rockers, hand ported intake, home bored 2.09" (53mm) throttle bodies, MSD 454 injectors(75 lb/hr), Holley 255LPH fuel pump, custum modded FPR w/Vacuum port added, Edelbrock TES headers, empty cat, SLP 3" stainless steel cat back, stock ECM & chip. Borg/Warner T-5 World Class, 12" Corvette rotors and clipers, GTA 16" wheels, South Side Machine subframe connectors, 1LE sway bars, 3.45 ring and pinion, Alpine sound.

 

balance the shaft ...and set the pinion angle....by shimming the trans mount.what ever the pinion angle is the trans must be equal.I'm usin the poly mount without any problems.There is also a thrust angle that may need attention

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87GTA,350,Auto,MAF screens removed,195 thermostat,cold start injector UNPLUGED,K&N,modified air intake,ADSchip,3:70s,3inch cat back Flowmaster single outlet,TPS.54,Bosch Plat plugs,base timing 6BTDC,22 MPG and runs like a bear,Bilstiens in the rear....,don't let yer meat loaf

 

I reckon' I can get it up on my buddies lift again and look at those angles - or actually, should the angles be checked on the ground... Arrgghh!!!

So, the theory is the Energy Suspension part isn't the same height as the stock piece - and throw's "stuff" (pinion angle, etc..) out of alignment?

I'll try to play with that stuff this weekend and let folks know what happens!!

Thanks!

Al

 

DO NOT install the 'torque plate' or the metal tab that comes with the mount (the piece that goes between the transmission and mount). Unless your car is pushing 500+ HP you do not need to install that piece. It raises the pinion angle plus transmits more vibrations because of it being metal. I removed mine and all the vibrations disappeared.

 

Did you check the height of the poly mount compared to the original? They are usually higher, changing the angle at the front U-joint. Leave out the spacer and/or lower the cross member with some washers to get better alignment.