The plastic door handle tubs on my car have been cracked for years and finally got to the point that I needed to replace them. I'd been looking for a really good replacement for a number of years and discovered that PI Motorsports had an excellent unit that was identical to the original de Tomaso part.
The first step is removing the inside door panel to gain access to the two bolts that hold them in the door. This page covers the panel removal. After the panel is removed, peel back a small amount of the plastic covering on the top back edge of the door to gain access to the bolts.
After the bolts are removed the handle assembly can be moved out of the door and the plastic door lock link can be carefully, carefully removed from the lock assembly by prying it gently off the ball on the lock arm.
View of the removed handle assembly.
The pin that holds the handle in place is swedged on both ends so it cannot be removed without cutting one end off. I chose to just bust off part of the plastic so I could cut the pin off with my cut-off wheel. My tubs were not repairable anyhow.
I used a nail with the end cut flush as a tool to drive the pin out.
Pin and handle removed.
Parts to be reused. The small hook shape on the spring is so it will move easily along the back side of the handle.
New tub. Note that the pin will be held in place with a clip.
View of the assembled unit. I used some light grease to lube the handle pivot and spring. On my car, the original bolts were larger in diameter and I had to replace them with one size smaller. Also, I had to add washers on the lock screws to keep them from bottoming in the lock threaded holes. Install the spring so the end that contacts the tub frame is in place with the other end loose. After the pin is in, then the loose end of the spring can be slipped to the side and then down into place behind the handle.
Reinstall in reverse order. I put a little grease on the lock arm ball, so the lock link would easily snap over it. I only tightened the tub bolts enough to keep the assembly from sliding around on the door to minimize the pressure on the plastic.
It is hard to tell exactly what causes the plastic to crack, but I expect using the handle to pull the door open, pulling the handle too hard or puling the handle hard with the door locked are likely suspects. I find it is best to use the handle to release the door latch and using your other hand on the door frame to pull door open . Anything that you can do to reduce the stress on the plastic is a good idea.
PI Motorsports can be reached at http://www.pim.net/ or by phone 714-744-1398.