Cushion
From Celica GT-Four / Alltrac - ST165 ST185 and ST205
Available Unit IDs: C01, C02, C03, C04, C05, C06, C07, S01, S02, V01, V02, V03.
Example: <google uid="C01"></google>, <google uid="C01" position="left" ></google>
The diff cushion is a bush consisting of an inner and outer metal plate with rubber between the two. It helps to resist rotation of the diff due to torque, without transferring vibrations. It tends to fail every 50-70K. Several have made a replacement or welded it solid, with some additional body vibration, but with no other negative effects. Its designed to reduce driveline shock so I (JB) cant see it doing no harm, but the quantity of cumulative damage is unknown so.
I have taken a standard one and totally filled it with PU rubber but it may be failing now (20K miles on) I assume because I didnt pre-treat the metal with the acid solution suggested by the manufacturer. If you buy the acid solution you effectively bring the cost up to that of a genuine part, which defeats the purpose. I'll be welding this one now as a test.