555 gearset & case differences

[86Shelby]

I know the '87/88 gearset and the '89 gearset are different and not interchangeable due to the syncho designs. Can an 87/88 gearset, shifter rods and forks be put in an '89 case? At first glance the cases appear to be the same...

[BadAssPerformance]

I think so... have to take all the gears, forks, etc, but case should be the same I think?

[rbryant]

Hmm... I thought the main shaft bearings were different or something.

-Rich

[BadAssPerformance]

Maybe... I thought the mainshaft bearing is the same, but the 87/88 shaft uses the shaft itself as the inner race while the '89 has a sleeve pressed on like the '90+ trannys?

[rbryant]

Maybe... I thought the mainshaft bearing is the same, but the 87/88 shaft uses the shaft itself as the inner race while the '89 has a sleeve pressed on like the '90+ trannys?

That could be...

If they are interchagable then why not make a 568 with the gears then instead of a 555? The 523 is easier to find these days and it doesn't need the chromo plate.

-Rich

[BadAssPerformance]

That could be...

If they are interchagable then why not make a 568 with the gears then instead of a 555? The 523 is easier to find these days and it doesn't need the chromo plate.

-Rich

The 89 555 gears are different than the A568 gears as are the cases

[rbryant]

The 89 555 gears are different than the A568 gears as are the cases

The gears are the same between 89 555s and 90 568s.

The main shaft might be different but the gears are the same.

-Rich

[BadAssPerformance]

I never matched them side by side with a mic and caliper but figured they would be slightly different as the shift forks and shifter mechanism is entirely different.

[rbryant]

I never matched them side by side with a mic and caliper but figured they would be slightly different as the shift forks and shifter mechanism is entirely different.

The gears are the same in the 89 555 and 90 568. I have confirmed this with Chris R in the past.

That was why I was using a logical inference to say that if you can put the 87 gears in an 89 you could also do the 87 gears in a 90 568. The wildcard is how the actual bearings on the main shaft go into the case.

-Rich

[TurboGLH]

555 cases are all the same. 87/88 gearset will fit just fine in an 89 case.

Also, the 89 555 and 90 568 DO have the same gearset. The shaft is the same, save for the bushing required to use the larger bearing, but the sliders for the synchro's are different. Swap out sliders and install a bushing and you can turn an 89 555' gearset into a 90' small spline 568.

One more point I noticed, you can't, to the best of my knowledge, use an 87/88 gearset in a 568. The different synchro sliders will not work with the 1 piece brass synchro's, they instead require the 89+ three piece steel-friction-steel design.

[rbryant]

555 cases are all the same. 87/88 gearset will fit just fine in an 89 case.

Also, the 89 555 and 90 568 DO have the same gearset. The shaft is the same, save for the bushing required to use the larger bearing, but the sliders for the synchro's are different. Swap out sliders and install a bushing and you can turn an 89 555' gearset into a 90' small spline 568.

One more point I noticed, you can't, to the best of my knowledge, use an 87/88 gearset in a 568. The different synchro sliders will not work with the 1 piece brass synchro's, they instead require the 89+ three piece steel-friction-steel design.

Great info!

I just wasn't sure about the syncros and sliders.

This means that the 523 sliders would actually be used when making a 568 from a 555 and 523 right?

It would be a good KC article/picture to throw this info together. We have the main shaft pictures from some 520s that will work for illustrating the differences in the synchros but I haven't ever see the slider differences. That would be a good picture to add.

As the 555s and 568s get more rare the hybrid options become more interesting. If there were more 87/88 555s it almost becomes intriguing to see if a custom set of sliders (for 87/88 syncros in a 523 case) could be made to create more 568s. Although I don't think we are to that point yet.

-Rich

[TurboGLH]

Great info!

I just wasn't sure about the syncros and sliders.

This means that the 523 sliders would actually be used when making a 568 from a 555 and 523 right?

It would be a good KC article/picture to throw this info together. We have the main shaft pictures from some 520s that will work for illustrating the differences in the synchros but I haven't ever see the slider differences. That would be a good picture to add.

As the 555s and 568s get more rare the hybrid options become more interesting. If there were more 87/88 555s it almost becomes intriguing to see if a custom set of sliders (for 87/88 syncros in a 523 case) could be made to create more 568s. Although I don't think we are to that point yet.

-Rich

You could certainly use the 523 sliders to make a 523/568 out of a 89' 555.

Pics could/would be good. I'm pretty much out of cars at this point. I still have my srt, but I think it will be going soon as well. Too much fun riding my bike to work on cars.

On the topic of 523 sliders with 87/88 gearsets, I'm not 100% certain they won't work, that's why I said to the best of my knowledge. I don't believe they will, but someone with some spare time and parts could certainly take a look and put the idea to rest, one way or the other.

[86Shelby]

Answered all my questions and then some, thanks everyone!