Weak cradle?

[GTRS Fiero]

The top rail in the picture is situated towards the front of the car, when installed. The rusty spot on the top left is where the trans mount is bolted.
There are two sets of holes, situated a few inches apart. This allows some flexibility in where the trans is mounted. (I have no idea regarding which trans "likes" which set of holes.) This area is where the damage usually occurs.
The pieces that are being sold on Pennocks are designed to fit inside the rail, from underneath.

For people who don't get this (me), is the weak spot at the green dot, or the red dot, in the image below?

[scottb]

the red dot. That is where the transaxle mount bolts up. that is the area that sees all the rotational force of the drive train, or torque of the engine. The green dot is an exhaust system hanger where the springs hook

[GTRS Fiero]

Thanks.

[ron768]

What is the plate that is mounted on the back rail?

[Raydar]

That's just a piece of insulation, kind of like tar paper. Similar to the ones that are installed on the sides.
It may be a splash shield.

[Raydar]

In reality, the entire 88 cradle is supposed to be weaker/thinner than the earlier cradles.
The 88 is apparently the only year that the trans mounts are tearing the metal of the rail.

[Fierofool]

Is it possible that the elimination of the torque strut shock on the 88 is contributing to that? 

[GTRS Fiero]

Is it possible that the elimination of the torque strut shock on the 88 is contributing to that?

Torque strut shock?  Where does that go?

[GTRS Fiero]

What is the plate that is mounted on the back rail?

That should be the rubber splash shield for the transmission, although mine is dhaped differently.

[Fierofool]

Is it possible that the elimination of the torque strut shock on the 88 is contributing to that?

Torque strut shock?  Where does that go?

85-87 V6's had a torque shock mounted to the engine and the cradle cross member next to the oil filter.  http://rodneydickman.com/catalog/product_info.php?cPath=22&products_id=348

[Raydar]

Is it possible that the elimination of the torque strut shock on the 88 is contributing to that?

I was thinking it was mostly for vibration damping, but I could be wrong.
(It was eliminated concurrently with the 88s going to internal balance.)

[Fierofool]

Never thought of that.  The reason I thought it was to take up torque movement was because my 2nd 85 developed a pop when shifting or accelerating and decelerating.  Sometimes there was a rattle while driving.  I found that the bolts had come out of the bracket that mounts to the cradle.  Once I replaced them the noise went away.