Last year I developed an interesting issue, and want to figure it out before track season this year. Car is a 1993 Prelude Si, with the M2S4 5MT. Currently running on a JDM H22, and an Exedy Stage1 clutch, stock flywheel.

My problem is, after well heated at the track, the car doesn't want to shift into 2nd gear. The trans shifts fine into 2nd at all other times, with no grinds. Once I have done 4-5 passes, I can't get the car into second, and the problem usually persists as I drive the car home, but is fine the next day. The only changes I made this last year, have been going from street tires to drag radials, and doing a 2nd gear burnout in the water box before each run.

I am wondering if I am just overheating 2nd somehow, and causing the syncros to bind up and not work? Is this the kind of problem I can fix with different fluid, or will it take new syncros? Current fluid is fresh Honda MTF, as of July 2010, with under 500 miles on it currently.

 

Sounds like you are overheating the 2nd synchro. The synchro is the brake for the gear. I would try a new carbon synchro on 2nd.

 

Most likely in need of disassembly and inspection, to replace the synchronizer. Are you getting nothing but grind period? As in no second at all, no matter the force?

Inspect the 1-2 shift fork, and shaft bearings as well. If you ride the shifter you will wear out the shift forks.

Using a more viscous fluid will improve shift performance, at the huge cost of possible lubrication problems due the the tight clearances. That can be a diagnostic thing, do that and then if performance improves a bit, you will at least know the synchronizer is partly at fault, and will require replacement.

 

Thanks guys!

When I have run into the problem, I am obviously trying to shift at high rpm/ load. If I get off the throttle and slowly rev match and apply pressure on the shifter, it does go into gear. When driving the car home from the track, shifting as normal, it is just a bit notchy and tough to get into second, instead of butter smooth. Since my third gear syncro has been a bit grindy for awhile, I should probably just pull the trans apart and do both of them at once. Might just be time for a swap to an LSD trans instead!

 

i would lose 3 gear after i would do some hwy. pulls when my diff bearings were too tight. check clearances.