Tel1sps

After my last track day I had a hard time getting the car into sixth gear. I never had any problems before outside of the normal (strange) stuff.

I drove out of the track without any problems. But when i got on the highway headed home I shifted to sixth and it did not go in. I at first thought I did something wrong with the shift went back to fifth and tried again. The same thing happened. I then tried a third time a little pissed (harder) and it went in. I've ben driving the car on the street now for a few days and it shifts ok, but feels a little grindy going in and out of sixth.

I plan on dumping the fluid and putting in redline, but I wonder if the syncro is going. Anyone else have a similar problem?

Tel1sps

Any advice on redline would be helpful also....

Ludedude

Don't remember exactly what the no-sixth problem marks the beginning of, but it's something to do with something being bent and will soon lead to the loss of fifth gear as well. I think twohoos had this problem...and it's been discussed before on the board.

A bad syncro will typically be accompanied by some grinding or notchiness and might be helped by a better tranny fluid like Redline MT-90. Just be aware that in your climate, going to something like MT-90 is going to cause the tranny to take some time to warm up in the morning especially in winter.

twohoos

It means you were grinding 5th gear on the track (probably missed a 2-3 shift and hit 5th). There's a detailed thread in UTH, but basically 5th and 6th share a sleeve that gets burred when you grind gears, and can cause you to lose the "non-ground" gear (i.e. grind 5th, lose 6th, and vice-versa). If you were able to force it into 6th you probably scraped off the burrs on the sleeve, so you should definitely change the fluid.

Redline MT90 works well on the track to help avoid this (but it's pretty balky when cold).

I'll look for the UTH link tonight.

Tel1sps

Yeah, I just changed the trans fluid with stock honda stuff and it feels a lot better. I'll see tomorrow when I go to the track again what happens.

Toohoos, Did you have to do anything to your trans to fix the problem? btw I did miss a shift to third and went into fifth, but I did not grind anything that I know of. I just lifted and downshifted. Getting the rollbar/seat/belts would help me a lot shifting coming out of the turns.

twohoos

It won't necessarily sound or feel like bad grinding when you miss the shift (esp. on track, where it's very rough/noisy anyway). The shaft speed differential is enough to overwhelm the synchro and burr the sleeve. Some people have lost 5th or 6th just driving on the street and skipping gears.

Did I have to do anything to fix it? Umm, yeah, I had to get new 5th and 6th gears. I got lucky and they covered it under warranty, but it was never quite the same. Today I still have 5th and 6th, but after just a couple minor grinds I've been forced to double-clutch into 5th all the time (5th gear synchro is completely shot).

BTW, be very careful on the track with the stock fluid -- limit the length of your sessions and come in at the first sign of trouble (usually a balky 2nd-3rd shift) to let the fluid cool. I use MT90 all the time, and it takes forever to warm up on the street (15-20 minutes minimum); I've resigned myself to just taking my time and shifting very gently on the street.

twohoos

Links:
https://www.s2ki.com/forums/index.php?showtopic=139607
https://www.s2ki.com/forums/index.php?showtopic=145017
https://www.s2ki.com/forums/index.php?showtopic=237209

Tel1sps

Thanks for all the info., very interesting stuff!!! It sounds like missed shifts and not properly rev matching on down shifts or skipping gears will cause the problem.

I'lll see how she holds up tomorrow, and I will take it easy on the high speed downshifts. The track I'll be on is not as technical as the last so it should not be too bad.

Thanks again

drewchie

I had this exact same problem... unfortunately mine required new gears as well. (covered under warranty ) 5th and 6th share a synchro that gets "pancaked" from the hard shifting. It'll seem to get better, but regrettably rear it's ugly head on your way home from your next track day.

Yours may still survive... Careful rev matching and double clutching will help to reduce the problem in the future.

cthree

I was having this problem with 6th so I replaced my transmission. Talk to hardtopguy as he may have a couple left and they are dirt cheap and smooth as silk. You can rebuild the old one and keep it as a spare. I think my old one is soon to be whored out as a working spare. I'm hearing that frantic call now: "Hey man, you still have that tranny sitting around? Well...".

It may sound extreme but this new box is awesome, maybe better than my old one ever was. I'm happy I decided to replace it.