Many of you who have this car know the rear end is very flexible and it can cause gear damage when it flexes.
I used very small K&S music wire to help strengthen it and my test results are very positive.
Remove the center gear system and cut a section of wire about 1 inch long and glue in place. I used good old Testors model glue (red label)
The center gear system is very prone to coming loose. Before you glue in place, lubricate the system as shown. If you get heavy handed with your adhesive, the lubricant will help prevent it from seizing up.
Then glue in place. I used Testors again and let dry a couple hours. Super Glue would work, just be careful.
Last night I tested this and it's just fine. The louder gear noise is from the larger spur and pinion mesh. I applied some break-in paste and this really helped it, although still not silent.
Hope this helps some of you.