I am assuming you are refering to the roll resistor(s) that can be seen from under the car. The are closer to the center of the car, a large round or oval piece with a large rubber snowflake inside of it?
When it is gone, your engine will experience too much movement. You may get a thump when the center aluminum piece reaches the limit. This would be under hard acceleration or engine braking though. As for prolonging its life, the only way you can make the ones you have work is talked about below.
Your local dealership or from
fordpartsonline. According to fordpartsonline, you will be looking at about $100 per mount to replace them. Yes, they are pricey.
As for prolonging its life. When I took my old ones out, the front resistor was to bad that the rubber snowflake actually fell out! Granted, I had been manually shifting the ATX for over a month with some of those shifts being quite hard. I took all for of my new, 77K mile mounts and filled them with urethane. It does take some dry time so your car would be off the road for a few days, preferably a week so the mounts could cure inside the warm house. If you picked up some used ones from the j/y it would allow you to keep your car going until you are ready. Anyway, I completely removed the rubber snowflakes after I had made some measurements. I drilled four holes in the aluminum tube that is in the snowflake and four in the outside of the mount, all opposite of each other. Run tiewire through those little holes to keep the aluminum tube centered in the mount. Plug the holes with a small dab of silicone. Seal one side (make sure its sealed too!) with some saran wrap and duct tape. Mix your urethane, pour, and wait. It took them about 40 minutes for the urethane I used to cure so I could take them inside.
I did use the hardest urethane that I could get my hands on that would hold up to the elements of an engine compartment. I would stay away from this grade, unless you are ok with extra vibrations being transfered inside the car. There are softer grades that would drown some of these down. Filling all four mounts is probably not required, but I did it anyway. I spent ~$50 to do the mounts, using the urethane I purchased from
McMaster - Carr. I used shore 94A urethane, so 80 or 60 would be a better choice if you dont want the vibrations. You will experience some with new mounts from Ford since their rubber will be in better shape then yours. Anyway, you want page 3298 in their catalog, just type that in the find.
FWIW, I have a set of ATX mounts if you want to do the urethane and dont want to go to the j/y. Shipping and their yours since they wont fit my car anymore. PM me.
HTH
