High Revs, Going For 4th With Fully Depressed Clutch

[scheris]

every other gear is fine, shifts well and fairly smooth, but come to 4th and if i try to quickly shift up to it, it will grind.

this is not an issue for any other gear, just 4th, the gearbox does have a quickshifter installed.

im thinking syncro's both sides of the 4th cog ? no ? maybe shit quickshift kit ?

[Mr Italy!]

Yeah mine occasionally does this too, with quickshifter installed also.

I think its just the syncros are a bit shagged, doesnt bother me too much though, good old R33 gearboxes

Edited September 2, 2006 by Mr Italy!

[Marlin]

every other gear is fine, shifts well and fairly smooth, but come to 4th and if i try to quickly shift up to it, it will grind.

this is not an issue for any other gear, just 4th, the gearbox does have a quickshifter installed.

im thinking syncro's both sides of the 4th cog ? no ? maybe shit quickshift kit ?

Synchro's gone. Maybe able to decrease the grind with a new/better oil.

Another thing to try if that doesn't work, and it's a little unorthodox, is;

hold steady revs on flat ground with nothing in front of you @ around 2000rpm. With your foot off the clutch (out) move the gear lever toward fourth gear slot (don't worry, it won't jump in!) and gradually increase the pressure with which you try to pull it into 4th. You'll notice the engine will actually load a little. Do it for up to 20 seconds, in increments of 5 seconds. It has the effect of "re-bedding" the synchro. Trust me, it works, bought me another 20,000k's in my GTR.

If all else fails, fix it, or put up with double clutching on the way up! {'cause we all heel and toe on the way down don't we people? I hope so! }

[Marlin]

Yeah, quick-shifters just wear our the synchro quicker thats all ('its always rushing the synchro)

[Jdfnq]

Mine does it as well....

Only when revs are high.

Thanks for the advice on re-bedding. I'll give that a bash

[markimak]

wow rebedding didnt think it would be possible. is there a DIY thread on that?

[No Crust Racing]

Interested to hear more on this 're-bedding business....