Here is a video of the outside of the Ford and the aftermarket passenger engine mount
Outside Comparison
Youtube of this is here:
Mount comparison
Please remember that the biggest difference is going to be the one you don't see - the rubber composition
The following is a pictorial showing how the mount is constructed internally. I took apart a
failed passenger mount. It is a Ford mount. The shock absorbing/vibration dampening oil
has long since leaked out
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Figure 10
Figure 11
Figure 12
Here is my $0.02 on why these mounts fail. The designers built the dampening mount so that the top of the oil chamber is sealed by a piece of rubber. This seal appears to have held up very well. The problem is the seal at the bottom of the oil chamber, it is made by the interface of the large chunk of rubber to the bottom of the casting, seen in figure 7. The problem is this, while the designers correctly assumed that this chunk of rubber would remain glued to the mount casting when the weight of the engine was basically pressing the glue joint together, they ignored the fact that the engine in the compartment is free to move around, and at times will move UPWARDS with a lot of force. As long as the rubber is pliable enough to stretch, it will remain glued to the casting. But, this mount is used under-hood where the engine heat will age-harden rubber. Once the rubber is hardened, an upward force will act to pull apart the bottom joint, and if that joint separates all of the dampening oil leakes out.
