So I have been planning out a suspension upgrade to my car and was thinking of all new poly bushings. At the same time I have been informed by the mechanic doing my differential that he noticed my motor mounts are just about gone and are probably causing vibration. We had a discussion about the pros and cons of rubber Vs poly mounts and bushings. Yes poly is much strong and will produce performance enhancements to your steering and handling; however, the ride will compromised i.e. you will fee more vibration. Poly is much tougher and will last longer but it would be good to get poly bushings that can be lubricated. Rubber will not last as long but will give you more vibration dampening but will not be as good as poly if you push the car in performance applications. I did a search and found a thread discussing the vibration issue. Rubber seems to last 15 to 20 years so just how long do you need these parts to last?

Does anyone have an opinion on this analysis?

Also, if I have a garage change my motor mounts is it as simple as removing the bolts holding the mounts in place, jack up the engine, install the new mounts and lower the engine?

 

From my experience, the "stiffer" poly didn't make a noticeable increase in vibration to me, nor my wife.

The hardest part about doing the mounts with the engine still in, is limited space the reach bolts. Not that it is so bad that ANYONE would pull an engine just to do mounts, just something to expect.

But your pretty much right....
Support the engine on a jack
Relieve pressure on the bolt
Pull the bolt
Jack/tilt up the engine (ONE SIDE AT A TIME)
Replace the mount
Reverse everything

Now...Your halfway done. Now do it all over again for the other side..

 

When I did the poly trans mount, I noticed some added vibration, but with just adding poly motor mounts, I didn't. Motor mounts are a pain...I'd do it right the first time and use the poly.

 

Once I get done replacing all of the bushings on my car some will be rubber and others poly. If you have poly engine and tranny mounts then I could see you having more vibration since alot comes from those areas and there isn't as much as a benefit there with poly. All of the suspension components benefit from poly, except for the rear control arms since I hear that they can bind with poly, and give you better handling. Thats how I look at it as there are pros and cons of both. My car is going to be setup like this.

 

I put a poly trans mount on my 92 & still had rubber motor mounts, got that vibration, so I just ended up putting a stock rubber tranny mount on.