The stock solid mounts that are sold at stores and through vendors are a crap shoot. You have to shake them to see if they are fluid filled. Sometimes even when they say that they are solid on the box they are still fluid filled. I have also read that sometimes when they say solid that they are not solid but just don't have fluid and still have the empty cavity for the fulid making them actually worse than the fluid filled mounts.
In my own experience I ordered and shook several mounts before I got a set of motor and trans mounts that I could not hear fluid in them. I even drilled into them to see if they were solid and guess what...fluid came out.
At that point I decided to make my own mounts. First you have to drill them to drain the fluid out. Here is picture of where to drill (The red dots). You want to drill at a slight inward angle towards the center of the mount:
PS- The mount on the left is a supposedly solid mount from ZZP.
I can be tricky to get all the fluid out but if you have a smaller diameter hallow tube to jam into both ends that you drilled, it will make it easier to drain out. You want to make sure to get all the fluid out. A little fluid is ok because what you decide to fill the mounts with will push some of the residual fluid out.
At this point you have to decide what you want to fill the mounts with. You want to look at the hardness or (Shore) rating of the filler you are going to use for the mounts. Most people that have done this have used 3M window weld which can be bought at most auto parts stores (This will be pretty close to the poly mounts sold at the vendors). You want the large tubes like this that fit into a caulk gun:
Amazon.com: 3M 08609 Window-Weld Super Fast Urethane Black Cartridge - 10.5 fl oz.: Automotive
Once you decide what you want to fill them with you can start by pumping the filler into one of the holes you made at the top of the mount. It can go into hard but that is the reason you have the caulk gun (Hopefully a decent one that won't just bend into a pretzel). Once you see the filler coming out the opposite side you can go to that side and fill from there. The point here is to get the mount evenly filled up.
You also need to fill the bottom of the mount. This can be done by taping or plugging the hole shown in the picture and filling it up (from the middle) untill you seem in coming out of the other holes (on the sides) like this:
At this point you should have the mount filled. Some people also put some of the filler on the top of the mounts like these examples:
Once the mounts are finished they need to cure. Some people have said 2 weeks to be safe or a month to be super safe. Once cured you can install them just like any other mount.
