An idea for a smoother/quicker shifting 568/523.

[86Shelby]

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.

[thefitisgay]

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[turboshad]

I guess I can shift as fast as I can put my foot to the floor and back so I've never seen it as a concern. What I really want to play with is the synchro teeth to help missed shifts due to synchro mesh. I've heard of the old boys taking out teeth to make a bit of a poor mans dogbox. Seems to be mixed reviews on the matter.

[Pat]

I guess I can shift as fast as I can put my foot to the floor and back so I've never seen it as a concern. What I really want to play with is the synchro teeth to help missed shifts due to synchro mesh. I've heard of the old boys taking out teeth to make a bit of a poor mans dogbox. Seems to be mixed reviews on the matter.

I recall Cliff Ramsdell cut every other tooth out of the syncros to a 520 as an experiment that Jon Genesky tested out. I talked to Jon about it and he loved it...right up to the point that he blew the diff out of it at the starting line. You should hit Jon or Cliff up for more details if you wanted to learn more about it.

[86Shelby]

I thought about trying the trick with removing some of those lugs but wasn't comfortable doing that with an already difficult to find gearset. If it didn't work out then I'd be up a creek.

If I get the chance I may go ahead and do this on Friday and see how it works out.

[Murphy]

Boosted Mopar's FAQ on on removing teeth from the syncros

http://boostedmopar.com/forums/showt...ynchro-gearbox.

[turboshad]

Well heck, one good experience is enough for me. Looks like it might be worth a try after SDAC. Not really looking to experiment before a long haul. Really the only major downside I've heard is that they will wear quicker but that's subjective. And when you only get to drive the car 5 months of the year I'm sure it will last a while.

[TurboGLH]

I built that GB to put into my hybrid glh, when I canned the project it sat around till Genesky volunteered to try it out. I don't know the eventual cause of the diff failure, but it wasn't running a posi of any kind and probably wasn't running pin retainers either.

A stronger diff could have allowed it to survive, or it could have broken teeth off of one of the gears and that tooth could have lodged in between the pinion and ring gear and caused the case to crack, with the total diff failure quickly following. Hard to say without a dissy and inspection. which was never done.

[TurboGLH]

If anyone has interest in a 520\555 crashbox, feel free to pm Cliff or myself. We'd be more than happy to do a few more, we might even be able to build a 4spd version of there was interest.

[135sohc]

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 tried this on the 3-4 rail and ended up losing the fork pads. The spring/roller also serves the purpose of pushing down on the rail to keep a 'preload' on it, without it the rail gets sloppy and easily allowed the fork to move around ejecting the inserts/pads.

[shackwrrr]

My experiment is going to be using 4 springs on each synchro. I know this will cause accelerated wear on the fork pads but i'm also going to try and figure something out with that.