[HO455]

With a trailing arm suspension you have less fore and aft movement of the drive line. There is only the movement caused by the axle traveling up and down and the little bit allowed by the rubber bushings. (No axle wrapping around the leaf springs) This amount of movement can be absorbed by the yoke at the transmission. The GM factory carrier bearing rubber mount is flexible enough to allow the drive line to move back and forth at least a inch and a quarter as the truck is driven. The transmission yokes are some what longer than what you find in other applications. I believe that this style is only found on automatic transmission trucks but I don't know that to be a fact.

I do know that this style of mount has caused lots of grief. The current replacement carrier bearings (At least most of them) seem to have the wrong kind of rubber around the bearing that doesn't allow enough movement, causing the bracket to flex until it breaks. With lowered trucks the the drive line is pushed forward and the bearing rubber is running at the limit of its designed movement causing the bracket to flex and break.

In addition the bracket is not very stout so in high torque situations it will flex from side to side.
They work fine for what they were designed to do. (Save GM some money ) Lightly loaded highway driven automatic trucks would go 100k miles without failures. Lowering and grossly overloading was outside of GM warranty concerns.