I mentioned this a while back when this was first talked about. I think you will find a lot of your problems are from using two different bushing materials. your motor mounts (most likely softer bushing) are fighting your trans mount bushing which is now much firmer.
You have to look as the motor and trans as one piece since they are solidly bolted together. And since this is the case you cannot use two different bushing materials because they will fight each other, which might be why the Z1 mount is 'loosening up" when in fact it is wearing out prematurely from fighting the vibrations that the motor mounts are allowing.
I learned all this the hard way with suspension bushings and it took me 3-4 bushing sets to realize you have to change out all the bushings that are affected to the same material other wise they are just going to fight each other.
So I feel that until you get some motor mount bushings that are of the same stiffness you will continue to have this problem.
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Project オレンジ 2009 (FUGLY) Grabber Orange Mustang GT // SLP loudmouth axle back // JLT intake // BamaChips Tunes // ...
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