[Kobinotkobe]

I have a 2007 Civic si that i just bought not to long ago, I noticed the transmission is very notchy and did some research and found out its probably my synchros. Now my question is should i rebuild it with aftermarket parts or oem parts? Or should I buy a new transmission? Also what is the best and somewhat affordable way?

 

[SniperBlaize]

Put some new fluid in it first. I highly recommend AMSOIL Syncromesh. It made mine noticeably smoother and got rid of 3rd gear grind.

 

[hondacayey06]

I have a 2007 Civic si that i just bought not to long ago, I noticed the transmission is very notchy and did some research and found out its probably my synchros. Now my question is should i rebuild it with aftermarket parts or oem parts? Or should I buy a new transmission? Also what is the best and somewhat affordable way?

I have a 06 civic si. TSB 08-020 came out after a lot of people complained. My car showed the problem around 33,000 miles. The dealer fixed at no cost. Worked fine until now with 175,000 miles. Close to 120,000 I had the cables from the shifter to the tranny replaced because 2,4,6 and reverse were REAL hard to shift. You may want to look at that too. I recommend go with OEM parts.

 

[Lilhendel]

Synchrotech or geardriven sell rebuilt transmissions that you can swap out and send back the core. That has the least downtime. Otherwise the synchrotech master rebuild kit for any Honda transmission is great if you want to learn to rebuild one.
Synchros help with gear shifts when the rpms are different between gears. It synchronizes the speeds so they mesh without grinding.