STI 6 Speed Gearbox issues
 

Ok, so we know the 6 speeder isn't the best of changes, but I need to address my STI's shifter before we head off to LeMans in 2 weeks, don't wanna get caught out with a dodgy shift facing some French Trucker head on!

I have problems shifting into fifth sometimes, a graunch if I try to rush it and don't follow the H pattern smoothly. A slight pull back before making the final push into fifth helps.
Otherwise I sometimes find myself stuck in the middle of the H when trying to get fourth.

I planned to change the oil and have been offered an additive 'Royal Gold' would that be a good idea to use along with a good gearbox oil?

Would a short shift kit help?

Thanks in advance

I know nothing about this 6 speed gearbox, BUT I 'know' that gearbox additives are not necessary if you use a good gearbox oil (rather like you don't need to add an engine oil additive to your mobil 1). Also, if your gear change is dodgy with the standard shifter, then the short shifter will only make it worse. I'm assuming that you've checked clutch adjustment (if that's possible), oil levels etc

Its most likely the syncro on 5th that needs replacing.

pretty much same problem on my spec c ,mines weak synchro,needs stripdown to fix :)

Sort of what I expected to hear though didn't want to!

Would replacing bushes give it a more 'positive' feel though as it seems a bit stringy if you know what I mean?:wonder:

Yeah. Oil level perfect, if it was clutch other gears would be affected I guess?

As a first step change the oil to a good quality semi-synthetic eg Castrol Driveline, Millers CRX 80/90 etc. (a full synthetic may make the "crunch" worse!) If you do, don't forget there are TWO drain plugs - under the front diff and the box itself, you have to remove a plastic cover to get at that one.
Has the oil ever been changed? If not I assume it's done less than 30,000 miles? The synchro really should not go in that short period?
JohnD

It's done 55k, and I can't see anything in the history detailing Gearbox Oil change. When should it be done according to the Service Schedule?

30,000 miles or 3 years - this includes the final drive unit as well. I personally did mine well before that, but that's me!
JohnD