Eplane what are synchros How do they work?

[DIRomberger]

Hey,

Have been studing up on cars. Searched forum couldnt find a thread like this so I thought i would start one.

What are Tranny synchros and how do they work?

Thanks!

[aspirin]

http://auto.howstuffworks.com/transmission.htm

[DIRomberger]

That site does wonders...

[DIRomberger]

Synchronizers
Manual transmissions in modern passenger cars use synchronizers to eliminate the need for double-clutching. A synchro's purpose is to allow the collar and the gear to make frictional contact before the dog teeth make contact. This lets the collar and the gear synchronize their speeds before the teeth need to engage, like this:


http://static.howstuffworks.com/gif/transmission-synchronizer.gif


The cone on the blue gear fits into the cone-shaped area in the collar, and friction between the cone and the collar synchronize the collar and the gear. The outer portion of the collar then slides so that the dog teeth can engage the gear.

[DIRomberger]

question what are the synchros made of and how do they connect? Since they are not dog teeth and dont connect that way how does it connect and get the driveshaft rod spinning at the right rpm?

[DIRomberger]

Are they like mini cluches? And I dont see them getting replaced or people having problems with them? <confused?> And even then dont they just do what the dog collor and dog teeth do anyways so it really just defeats the purpose of the dogteeth there just there for added grip?!

[enthennd]

Uh, they do get replaced, and people do have problems with them. They can wear down and tear up, and sometimes be expensive to replace?

[MKE]

yeah, i've had syncro problems on both my manual cars (an 01 tiburon- they were replaced by the place i bought it, and my gts syncros are getting replaced soon under the extended warranty)

from what i've read, 2nd gear seems to be common on most cars, but on my tiburon 3rd was an extremely common one to go bad.

There are special tranny fluids out there that are supposed to help reduce the wear on the syncro's, but if you notice them going bad (grinding into gear at low rpms especially) i'd start saving up a ton of money (my tiburon had a bill of 1800$ for all syncros to be replaced).

[DIRomberger]

But that still doesnt answer my question?

1. Are they like mini cluches?

2.they just do what the dog collor and dog teeth do anyways so it really just defeats the purpose of the dogteeth there just there for added grip?!

[DIRomberger]

I mean if they get the rod spinning to match the gear then let the teeth ingauge then y do you need the teeth other than more connecton ?

[Ryuujin521]

But that still doesnt answer my question?

1. Are they like mini cluches?

2.they just do what the dog collor and dog teeth do anyways so it really just defeats the purpose of the dogteeth there just there for added grip?!

1. Yes synchros make frictional contact to SYNCHRONIZE the selector and the gear set before they come into contact. So in a sense sure they are like mini clutches

2. Im not even sure exactly what your asking but the synchronizers don't lock you into gear from what i understand. The dog teeth on the selector collar are what actually locks into place and puts you into gear.

[Wilke]

they don't have enough contact patch to hold on their own...yes they are "like" mini clutches, and yes they do wear down and need to be replaced(just not nearly as often as a normal clutch), And I believe they are a type of brass(someone correct me if I am wrong) which is why some gear oils souldn't be used in a tranny (i.e. gl-5 lubricants) because they degrade brass.