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The Big Fist

Gearbox not selecting 5th/6th at high rpm

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Looks like the throw out bearing has been running on the pressure plate fingers.

Could this be part of the issue ? A few laps before it started locking out fifth it did a massive slip.

 

If I get into strife with the gearbox I'll send it to a shop but it should be ok !

 

cheers

IMAG1189.jpg

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Orright bit of an update.

Box is out and pulled apart.

No metal, all looks pretty good but I think the oil was in there too long.

Bearings good, nice and smooth.

 

Reverse synchro baulk ring totalled fisted. No gap, would explain why it's hard to select.

Fifth synchro baulk ring has gap within tolerances, about midrange. With mild pressure it will slip on the cone but with decent pressure it wont.

I think i found the problem. The selector coupling has some worn sharp edges which are also on on the 5th synchro hub. I doesn't slide nicely. I think it is getting caught on this at high rpm and wont select the gear, like hitting a brick wall.

The other concern is I couldn't seem to find the small ball behind the 6th gear. Anyone know the function of this ?

 

Donny, be interested in your thoughts on the above seen as I am sure you've played with these a lot.

 

While its apart I might as well weld the circlip on 3/4th and maybe put new synchros throughout.

 

Also found the shift forks and coupling were in the higher range of wear but within tolerance.

 

If anyone wants pics I've got a fair few.

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Can u email me some pics plz? Also the circlip that gives us all grief! Pulling my box out today :) stuart_cali@hotmail.com

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The circle is on the back of 4th, you have those 2 half circle hardened steel pieces and then a pissa little circle that holds those 2 together. That's the problem do a descent tax weld against the dick ie circle and the 2 half circle clips on both sides this will stop it from coming off but if you ever need to remove it your going to have to break or grind it off.

reverse being f**ked is pretty common, there a constant mesh gearbox always spinning just due to tightness and friction it pays to double clutch into reverse or really hold the clutch for a bit but quick shifts into reverse kills Em.

you will be surprised I have about 40 or so stripped down 5 speeds tones of spare good parts from various broken boxes.....no good reverse gears or baulk rings.

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Awesome, thanks donny. Also do you know where I can source parts from for the box?

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Ahajahaha sweet, you'll get a call from rob Novak from definition Motorsport to source parts for my 6 speed. Can you pm me your number.

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Similar symtoms to my other post in the next gearbox thread. Mine died all of a sudden without being able to select 5th, 6th or reverse. Prior to that, when selecting 6th gear, the reverse bridge would engage and it ins't meant to.

It's kind of been answered already, but basically what this guy said.

Mine stopped selecting 6th and sometimes 5th (plus it would stuff up on rear gear too) just when driving for too long on the fwy.

My thought is, when this happens, the box is on the way out.

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