The 568/523 tranmissions have 4 detent springs which are located directly under the shifter housing with roller followers under them that follow ridges in the shift 4 rails. They are similar to a roller lifter for a V8 engine but on a much smaller scale. They give a nice positive feel to the shift mechanism when going about your regular driving. I find them to be a bit of a pain when I'm runnin through the gears in a hurry; you first have to overcome the pressure to get it out of gear, then after slipping through nuetral you have to apply yet more presure again to overcome the springs and the synchro assembly to get into the next gear.
I have two thoughts on how to lessen this extra effort.
1. Find some springs that are the same length as the stockers but exert less pressure. This may or may not work out since having reduced pressure may allow the roller followers to turn and leave you stranded not being able to get in or out of gear. There are no guides that prevent the rollers from spinning in thier bores; just spring pressure and the assumtion that they will stay straight and true becasue they are pressed into the recesses on the shafts.
2. Remove the followers and springs all together. I would only do this for the 1-2 and 3-4 rails and likely leave them in for the 5th and reverse rails. I'm not one to want or need to powershift into 5th gear, and knowing full well that I'm in reverse is a good thing. I think this may be the way to go. The '89 555, which lacks any additional detents like the 568 has, has a gearset that is identicle in operation to the 523/568. It has no issues with popping out of gear.
Have you heard of anyone doing this before? What are you opinions on this for a quicker shifting trans?
I really miss being able to powershift without worry of missing a gear like I could in the GLHS and GLHT(both had a rod linkage 555 for several years) and feel this is one thing worth looking into since my cables in the R/T are nicely lubed and slide easily.