I built a 950# street legal Honda 954 powered car in Oregon. What a hoot to drive. I have no history on the used 03 954 engine. The transmission functioned great until I started going beyond 6000 rpm. I assume the shift fork is bent or shift dogs worn since it either completely misses 2nd or comes out of 2nd. I will split the cases myself but need advice as what to look for. ThanksHerman Pahls

 

Most likely it's the fork. 950# and a couple of hard shifts from 1st to 2nd prolly did it in. I don't know if they make a heavy duty aftermarket shift fork but it sure would help in your case. If you don't already have one, a shop manual would come in handy. I am not familiar with the 954 trannies but the 1kRR has many pieces that look the same but are indeed different ... and it matters.

 

I honestly can't help you on this one besides telling you I don't "think" you need to split the cases. All you need should be under the left side engine cover. The guts of the trans are inside the cases, but clutch, shift fork, all that jazz should be accesible without major surgery.
I do, however, want to see some pics of this car

 

I'm in Portland and want to have a look at this crazy vehicle of yours!

 

i had the same prob with my clutch i swapped it for carbon fiber no probs now, and u dont have to split the case just drain the oil and take the cover off everythings there just follow the instructions make sure u do the torques right and dont mix anything up