Hi ALL,

i’ve got a question regarding 5 speed gearbox:

Do you all use stock synchros and other parts of gearbox ?

the idea of the question is to reduce frequent gearbox rebuild after fast shifting
600-650 N/M brake my gearbox often. Crunch of the 2nd and 4th gears...

How could i improve this situation? Is there any reinforced aftermarket gearbox parts? Or no need use them?
Short shifter plays negative role in this situation?

 

For start, use Tephra flatshift option on the stock ecu... makes shifts much easier on the gearbox

 

There are upgraded 3rd and 4th gearsets from PAR (can be sourced from TRE in Michigan, or English Racing in Washington).

That torque is only 450-500lbft in US numbers. You really shouldn't be breaking stuff that often at the level.

 

A short shifter will reduce synchro life, yes. Clutch drag can also accelerate wear on synchros, but driving style plays a big role, too. You shouldn't be ruining synchros like crazy unless you're doing something wrong.

 

Really? I don't see how. I mean if you suck at driving stick I could see it making you suck worse, but I don't see how it would effect the trans at all. I would think because of the shorter throw you actually have less leverage to bang on synchros. A short throw is literally the first mod I do on all my manual cars and so far I haven't had to dig into any of them. I'm coming from a completely street/DD context though, not motorsport.

P.S. Not trying to argue, just looking to be educated by people with more/different experience than I have.

 

im with biggie... i wouldnt think a short shifter would have anything to do with it.

 

You're right, I should have been more clear. Short shifters quicken the action of the synchro - if you shift faster than the synchro can brake for, it will mash the engagement teeth on the gear, which could cause the crunch that OP may be experiencing.

 

Yea I have done it a couple times in my Evo that way when I clutch out to quickly as I am shifting into the gear. Usually it happens because I clutched out before I could get it into the gear.