^^^Good review & information. These failed synchro's should go back to Synchrotech to be examined. Maybe they had a bad run of them?

Looks like youre well versed in tearing down & re-building the EvO trans. What assembly issues or driving operation could have contributed to this issue?

 

Assembly/driving wise, nothing could have caused this in terms of mechanical operation.

If the synchro was installed dry, I could see the first few miles of driving potentially affecting the longevity of the carbon due to too much heat/friction before the fluid was able to be pumped through the shafts and the gears took an oil bath but one would think all of the synchros would've suffered the same fate, especially the synchro right across the street (4th).

That's the puzzling part, 3rd was the only one to suffer this issue. And again for the record, 6 years and 10k+ miles of use and not a single problem until now. The synchros I removed could actually be reinstalled and the carbon lining is still MINT. This is in no way a bash of the product but more of a "this can happen" situation. When I ordered these the rep was awesome over the phone and I actually received them 2 days after order

 

Just spoke with David Ruiz from SyncroTech.

He was extremely understanding, friendly and offered a fast resolution to get me back on the road. I can't thank them enough for how they're handling this situation.

While we are not exactly sure what the root cause of the failure is, new units are on the way and these will be going back for failure analysis. Some possibilities are: Synchro being "cocked" slightly when being installed which will hurt the carbon lining and causing it to damage the adhesion/Bonding process failure but an extremely low amount of total units sold have experienced this.

IF SyncroTech does see this, I am very grateful for the help. And its worth mentioning again, 6 years 130-140+mph trap speeds and 8-9k RPM shifts and this is the FIRST issue I have experienced. Looking forward to getting the new units and getting the car back together!

 

What was the resolution and what's your review the second time around? I have my trans apart and am about to order their master rebuild kit. Any tips you can enlighten me with while assembling the transmission. What was the clearance/pre-load you used? Thanks!

 

Syncrotech sent me new synchros, they lasted a long time and through a lot of abuse. I did a refresh this winter, and 3rd synchro (same as last time) failed immediately except this time 6 miles into the test drive i could tell and parked it before ruining anytning. It was lubricated, it wasnt uneven when installed and moved freely the entire time. I have found through the years that the bonding of the carbon is inconsistent and sometimes you'll see a gap in the ends of where the strip is layed or it'll be slightly crooked. I am not saying this is the mode of failure just an observation.

With that being said, many shops use them and have great success, probably 10:1 for success versus failure but it is more real for me because I do the work and have seen it. The carbon synchros take missing a gear much better on a very high (600hp+) car. Ive missed a gear on fresh oem synchros and it was ruined immediately. Not that anyone should miss gears but because of that alone I'll stick with carbon.