105 Synchro Sleeve Differences

**asuppe** · #1 (**permalink**) 11-18-2009, 09:07 AM

I am comparing two new 105 synchro sleeves. The one on the left is an Alfa part, the one on the right is some aftermarket part. If you look closely, you can see a difference in the profile of the teeth. The aftermarket part has more surface area, while the Alfa teeth are chamfered to the tip. I am guessing the larger teeth on the aftermarket gear are for added strength, so the teeth last longer.

Does anyone have hard info on the difference? The color difference makes me wonder if the shiny Alfa sleeve is not moly coated.

Thanks!

**Alfar7** · #2 (**permalink**) 11-18-2009, 06:06 PM

the aftermarket Syncro Rings are cheaper to build.
The flat surface at the contact point will develop a "lip" as it is hammered by the dog teeth with use. It will become hard to engage the gear and harder to disengage.
They can eventually destroy the syncro band and even pull out the dog assembly from the gear, and then the gear will not disengage.
Grind the taper on them as on the OE.