3rd gear notch

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Jun 24, 2014 | 08:57 PM

#21

sonic9

Thread Starter

Joined: Dec 2012

Posts: 395

Likes: 7

Quote:

Originally Posted by TheBigS

Quote:

Originally Posted by Billman250' timestamp='1390955229' post='22987950

Third gear bump is very common. I have been able to instruct all my guys to avoid it.

Rev to 5.5k.

Shift swiftly, and firmly. Shift immediately after putting the clutch pedal to the floor.

As long as you get the shifter into third before the main shaft has started to decelerate past the equal speed of third gear (in short, before the revs fall back down), it will go in absolutely seamless. I promise you that.

The bump is actually the syncro speeding up a mainshaft that has fallen under its current speed. The syncro is supposed to slow the main shaft...as the revs fall.

The reason is simple...2nd and third are far apart shifter wise, but close in ratio gear wise.

If that doesn't pan out, then you have developed burrs on the 3-4 shift cog.

Wide open throttle operation in third gear, accel and decel from 9k to 6k, can flatten the burrs and cure it 100%.

This has proven effective on 5th gear lockouts, the mechanics are no different for third gear.

Sorry to comment on an old thread but this thread describes the 3rd gear bump most accurately to what i have in my car, i noticed you said that you have instructed many people to stop this now i have not done what you described to de-burr 3rd gear yet and while i have tried to do what you described as swiftly shifting i might not have done it properly. Is there any other helpful advice you can give me? btw my car is a 2009 with 25,000 k. Thanks!

Honestly, what helped me was shifting in the H pattern instead of a backwards N pattern...shifting on the diagonal is when i really would feel that bump...also..shifting above 5k i rarely feel the bump and its really smooth..ive just come to accept that this car needs to be revved to operate smoothly...it can be smooth shifting at low rpms but IMO...it will never be as smooth as "normal" cars....

I own a 2008 civic 5 speed thats smooth no matter what speed or RPM i shift at...just the nature of the cars i guess...if something is wrong with my tranny...i guess ill replace it with an ap2 one when it goes...but the only grind ive ever gotten was actually just yesterday when i was doing about 7 mph..i went to downshift into first and accidentally went into third..got a small grind..if this car is supposed to operate at high rpm then that would explain the grind....Ive been driving all differnet types of manuals for a while now and if i did that in any other car it wouldnt grind...this car is very different from other cars though so ill just accept it and love the smooth shifting high rpm nature of this car

Jul 30, 2014 | 01:54 PM

#22

vtec9

Registered User

Joined: Dec 2005

Posts: 10,106

Likes: 5

From: Connecticut

My tranny was buttery smooth for 201,100 miles, and suddenly I've noticed notchy shifting into 3rd, 4th and 5th literally overnight when shifting below 4k about 50% of the time (never had a problem at low rpm before). I changed fluid 1000 miles ago with Honda MTF. Maybe I'm going insane. Pretty sure I got the full 1.6qt in there. Maybe I'll change it again this weekend and bleed the clutch too.