Prothane vs. ES trans mount
When I did my H/C/I/E install a while back I installed ES poly engine mounts and trans mount.
I have a vibration at 2000-2500 rpms. It does it in neutrul(6 speed car)and going down the road. When driving I can feel when I hit 2000 rpm.
I have a SLP underdrive pulley and Monster 3.5 clutch, well I did have a Monster 3.5 clutch until I killed it.
I figured my vibration was from
1. SLP U/D pulley, even though I've never read any problems with them as compared to other U/D pullies.
2. The clutch assembly I had wasn't balanced correctly.
3. Poly engine mounts
4. Poly trans mount
5. Combination of 3 & 4
The trans is out right now due to the as for mentioned clutch dying. I will be getting a new Monster stage 2 clutch here soon and I'm thinking about replacing the ES trans mount with a Prothane.
I did use the shim included with the E/S mount. As best as I can remember, the ES mount itself was not as tall as the stock mount. With the shim installed they were the same height.
I'm going to have the driveshaft balanced while its out. However I don't think that is the problem because it does it in neutral. You can feel it through the entire car. It's kinda of a pulsation if that makes sense.
I don't believe its engine related, I've replaced the plugs and wires and its still there. No misfires that I can see on the scanner.
Without knowing exactly what problems/NVH the poly mounts cause, I'm can only guess thats my problem.
Thanks for any help.
J
I believe in poly trans mounts, but many do not. The reason everyone hates them is because at first they create vibrations, but they DO soften up after some driving (I noticed mine soften up maybe 2 weeks of light driving). I have NONE of the initial vibes I had when I first installed it. If you put one in, give it time to soften up, it will. I like them because they keep the shifter firm in place, which to me, improves my shifting.

By the way, you will still feel an out of balance driveshaft in neutral.
I'm chasing a new vibration that happened after I broke my stock driveshaft. I've narrowed it down to the tailshaft bushing, which I have ready to replace, I'm just waiting for a good time to do the work!
My shifter no longer seems like it took a Viagra when I stomp on the pedal either.
The vibes WILL calm down after a week or so.
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I figured my vibration was from
1. SLP U/D pulley, even though I've never read any problems with them as compared to other U/D pullies.
2. The clutch assembly I had wasn't balanced correctly.
3. Poly engine mounts
4. Poly trans mount
5. Combination of 3 & 4
Start by shimming the crossmember lower with washers and longer bolts. If resolved, shop for a lower height mount using the above thread link.
With regard to durability of the trans. mount and NVH, get the torque arm off the tailhousing and onto a non-stock or modified crossmember. Then you'll have a quieter car that's durable. The rubber mounts last a long time in cars without torque arms.
But in the end the OEM rubber style tranny mount is the best bet. I've never killed one and a fresh rubber mount works great with no vib issues. I get mine from Napa for around 10 bucks. I can get you a part number if you want it
Yeah I was surprised, it's a really nice piece too, very stiff. I have a NAPA warehouse right up the street for me so they have everything.. IIRC it was like $9 and some change.

Also put my founders poly LCA's and panhard in, Bilstein shocks and BMR lowering springs. I got both founders pieces brand new for 50 bucks off craigslist :O and pulled the shocks/struts off my 383 car, they are still brand new. Great, great, great improvement.











