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Old 03-17-2015, 09:36 PM   #1
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Default Broke 5th gear in a 6th speed, WTF?

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The white NA6 I work on just broke 5th on the street with another shop driving it, apart from asking what the hell you are doing in 5th breaking gearboxes on the street, how can this happen?

I dont play with a lot of gearboxes but it seems almost impossible to me.

Dann
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Old 03-17-2015, 10:15 PM   #2
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hp/tq?
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Old 03-17-2015, 10:26 PM   #3
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Also what clutch and flywheel? Curios to know if this will tie into the other thread on light weight flywheels.
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Old 03-17-2015, 10:41 PM   #4
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Exedy cushioned button, lightened stock flywheel, nothing crazy.



Dann
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Old 03-17-2015, 10:56 PM   #5
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Quote:
Originally Posted by nitrodann View Post
Feel free to move if needed.

The white NA6 I work on just broke 5th on the street with another shop driving it, apart from asking what the hell you are doing in 5th breaking gearboxes on the street, how can this happen?

I dont play with a lot of gearboxes but it seems almost impossible to me.

Dann
My guess is it broke the teeth off of 5th gear. Damn that sucks. And damn 350whp is a lot! (I'm jealous!)
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Old 03-17-2015, 11:09 PM   #6
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I didnt realise till I asked around that the 1:1 gear on an AZ6 has gears with teeth on them..

So yeah I guess.
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Old 03-18-2015, 12:57 AM   #7
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There is no gear teeth loaded in 5th for the 6 speed. In 5th the input and output shaft is locked together with the 5-R selector ring. Although I have heard people call the primary gears that drive every gear accept fifth as being fifth which seems odd to me. To loose drive in 5th you would have to break the selector ring for 5th. Never herd of that happening and it seems highly unlikely. Maybe if you bend the 5-R fork so it won’t select 5th you could call it a 5th gear failure.

Also can’t see the primary gears braking that easy in the 6 speed. They are huge about 20% wider than what’s in my Quaife box don’t appear to be a weak point. 5 speeds break the primary gears at about the same rate as they do 2nd and 3rd gears.
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Old 03-18-2015, 01:29 AM   #8
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That's basically what I would have guering and it seems I have since been incorrectly informed.

So its got a broken shifter or selector ring.

You are running this sort of power aren't you Bundy, did you break 6 speeds at this level?
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Old 03-18-2015, 01:58 AM   #9
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Quote:
Originally Posted by nitrodann View Post
That's basically what I would have guering and it seems I have since been incorrectly informed.

So its got a broken shifter or selector ring.

You are running this sort of power aren't you Bundy, did you break 6 speeds at this level?

I've broken multiple 6 speeds mosty when using Hoosier tires lots of grip. usually 4th gear one second gear. also broken some thrust collars effecting third and 4th with gears shifting for/aft on the shaft. never had syncro, selector, or shift fork issues.

I have heard of people bending the 5-R shift fork I'm not sure what happens when they do that. I could imagine it not being able to get the selector ring to fully select 5th though.
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Old 03-18-2015, 02:14 AM   #10
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Thankyou, we have found a 6 speed to run this weekend and we will pull this down and take photos when it gets fixed.

Cheers,
Dann
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