Transmission Synchro
 

I could have revived a couple old threads that I found in search, but I want to get straight to the point here.

I need to build a beefier transmission over the winter, has anyone found a valid syncro replacement that’s not brass, is there a vendor that sells syncros, shifter forks, bearings or any sort of rebuilding kit.

Are the s2000 ap2 carbon syncros swappable?

All my internet scowering and research is turning up dry.

Hmm, interesting question. Our transmission is supposed to be the same as the S2000 (with different gearing i think), but I can't recall heading about anyone using S2000 internals in ours.

Subbed in case you get an answer.

you might check with these guys Synchrotech - Honda & Acura Transmissions

we've run one in the race car for years (its a honda) and it has been better than stock.

it won't help because honda uses a different part number system from Mazda, but if you need to look up a part its here http://estore.honda.com i see as usual honda doesn't sell the synchro seperate

was always my understanding the syncrhos for the s2000 were a weak point in that transmission and the az6 put in the s2000 was also the weakest of the az6. best bet would to just contact to manufacturer and see what they have to say.

Posted From RX8Club.com Android App

Posted From RX8Club.com Android App

This is true, the ap1 s2000 used brass like us making it the weak point.

ap2 s2000 is a carbon steel syncro.

would be interesting to know, i'm working on one now and the only options i have found are OEM for the internals.

if it were going to remain stock i would say just replace the transmission with a used unit, they're assembled in a bit of a basket case manner and not the easiest of transmissions to work on.

i'm sure an FD transmission with an early bellhousing swap might even be an option, parts are cheaper but the gearing might not be to your liking.

not sure

You could swap in a Series 2 transmission.

I am also interested as mine is going very shortly. I've looked into the s2 trans a bit. But everyone seems to have a different opinion on it. Subbed.

I love my S2 Trans, makes the entire driveline feel more rigid and defined. Throw on a syncro saver and it feels bulletproof, just need to align my PPF to reduce flywheel chatter and all will be well again.

Look at the Koni challenge racecars, they used to fly through S1 transmissions but the S2 transmissions seem to stand up to the beating. I know my trans will fail from track use eventually and when it does I'll get my hands on an S2 trans.

See, this is the stuff!

Thanks for your input once again.

Do you know what exactly makes the s2 transmission better? Different materials? Or just tighter tolerances?



My home track is an old motorcycle gp track, lots of gear changing and tight technical corners that has me constantly doing the 3rd to 2 gear drop, she's really starting to hate me lately so it's been double clutching until rebuild season.

So these synco savers are the real deal then? They looked awkward and gimmicky so I totally overlooked them, but if they are proven then yeah I’m on board with that.

Cart Price Check Part:03-0000-P6Y1

Might have give myself an early Christmas present. 8 )

Catalog

pics https://www.facebook.com/media/set/?...9450697&type=3

6spd dog box

1 to 4gears dog then 5th and 6th syncro mesh

or Buy a 5spd rx8 and dog box gear set

SAENZ Transmisson Europe

the S2 transmission is a completely different design.

the S1 trans is made by Aisin http://en.wikipedia.org/wiki/List_of_Aisin_transmissions so its like an ambitious corolla transmission.

the S2 transmission is a Mazda design, and its related to the 5 speed Mazda supplied to Ford* for a decade or two, before they added a gear and plopped it into the miata, and then Rx8

the S2 (P type) has had problems with the 3rd gear shift fork, but i think all the Rx8 transmissions should have the updated one, which is incredibly huge.


*it saw use in the Ranger/Mazda B truck, and maybe the vans too, in the 90's Ford used Mazda to supply transmissions as they didn't seem to be able to make anything that small/complex themselves.

I really wish people would stop posting this falsehood. They are both made by Aisin and both share a model designation within the Aisin design model, but otherwise they are about the same as an apple and an orange are the same because they are both fruits.

The RX8 and NB Miata 6 speed have the same center casing and some swappable internals. Unfortunately this is good for their trans as the NB model has nothing of value for OE parts on an RX8. If you can find aftermarket upgrades for it, then maybe

I just bought an S2 trans and will be making the swap over the winter. I have a bunch of S1 transmissions I'll be getting rid of in the near future, everything from at least 3 broken ones (2nd gear blown out on the countershaft & main), a high mileage used one that is still supposedly good, one that had a high dollar rebuild but currently has a bad bearing and is otherwise solid, and one good low mileage trans that the S2 will replace.

IMO there is nothing wrong with the S1 trans synchros. They typically see damage from other things like poor driving, wrong or bad oil, clutch issues, other internal trans issues like bent forks, worn bearings, flexure under high loading conditions, etc. The S2 trans is not just beefier inside, the casings are much more rugged & heavy duty (and less prone to flexure under loading) too, which is why it weighs about 20# more than the S1. That said I did have an issue once out of all my S1 transmissions where a 3rd gear grind ended up being one of the synchros breaking (there was a pic posted on here once long ago, not sure if it still exists). This was the only synchro I ever had fail out of 7 or 8 transmissions I raced on.


.

One thing to consider, the RX8/MX5 has the unique PPF arrangement that requires the trans to be a reinforced rigid structural member. It has to be designed to handle the additional loading.

S2000 trans

http://secure.hostdeziners.com/speed...mages/2253.jpg



RX8 S1 trans

https://www.rx8club.com/attachments/...ocal-xx-rh-jpg


the new FRS/BRZ also has the same Aisin model

http://i.ebayimg.com/t/2013-13-SCION...8Kg~~60_35.JPG

I was more concerned about the internals, not the physical transmission.

Your assumption is that they all use the same diameter gears/syncros, same shaft C-L spacing, etc. If this were the case we'd have seen many options for gearing swaps etc. What few options exist are very expensive. The enthusiasts in Japan have access to all this stuff. After this much time it would have already been seen if it was as simple as some people have tried to portray it.

The purpose of the pictures is to demonstrate how the supposedly identical transmissions are anything but this .... they don't have the same bellhousing pattern, input shaft spline/diameter/length, casings, and so on. Each manufacturer has their own application design criteria.

.

Thank you my good sir! and also to everyone else for contributing.

S2 tranny it is! I wonder if it will fit under my three this Christmas! (I havnt put up a tree in 4 years :tear: )

I had a dream couple nights ago that I sold my TG S1 and got a VR S2 on white volk ce28's she was so smexy but I’ve gone too far with the S1 and I’m original owner, it would be like giving away my dog to the spca.