My '89 came with a slightly different looking steering coupler.
It was heavily worn, and IMO a very poor design. They do sell a kit to rebuild the insides, if you can find it.
I replaced my steering gear and replaced the original coupler with a steering U joint from Flaming river. The difference is night and day.
http://www.summitracing.com/parts/FLA-FR1755/
This one bolts directly onto the steering gear. I also bought an 18 inch piece of dd 3/4 inch steering shaft. I cut it down to about 14 inches, and slid it 10 inches inside the steering column.
I did a write up on this procedure with photos on other dodge "talk" forum.
Google it, register, and search my posts. If I could attach some URLs here, I'd post some high res photos here. Here are some links to the photos.
http://i557.photobucket.com/albums/s...t/IMG_2748.jpg
http://i557.photobucket.com/albums/s...t/IMG_2729.jpg
http://i557.photobucket.com/albums/s...t/IMG_2745.jpg
http://i557.photobucket.com/albums/s...t/IMG_2750.jpg
http://i557.photobucket.com/albums/s...t/IMG_2756.jpg
http://i557.photobucket.com/albums/s...t/IMG_2759.jpg
If the base of your steering column looks the same as mine you can do what I did.
If you decide to rebuild your coupler, you have to unbolt the steering column from the floor and pull it out a few inches to remove the coupler.
I just cut my old DD steering shaft and was able to remove it without unbolting the column. I had the new steering gear in place but unbolted, and had to move it to the side to slide the Long DD shaft into the column.
If you unbolt the steering column, make sure to disconnect the battery first.
I'll be glad to answer any questions you have, if I can.
The dampener only helps prevent wear on some steering components when on rough roads or helps in the event of a front tire blow out. It does not reduce slop. It actually adds drag and slows down the steering. I removed mine after the above modifications, as I no longer drive Baja's washboarded roads.
There is a way to tighten the steering box as well. I did that and got a noticeable improvement, but when the gear really started leaking badly, I then replaced it.