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Discussion Starter · #1 ·
Today, i installed a override on my new 4mill engine. It's an override 1-5,N down dunable from wcr.

I follow the instruction on the box ( 1min on first with pulled clutch ...)


I try it a couple of past on my home test track and a couple of the, the transmission shift by himself a gear. What is the problem???

I think it's possibly my clutch... For today, i use them with a standard clutch, no rdz spring or lock-up.


What could cause this problem?


thank you

bansheeqc
 

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Discussion Starter · #3 ·
QUOTE (Kawiking @ May 17 2009, 05:50 PM) index.php?act=findpost&pid=43009how many times did it shift by itself ? and was it in the same gear each time ?


2 time on about 30 pass on the load.

and an another time: i run very slow (my engine rev like 2500-3000 rpm) in 1st to get it to my garage, and the engine bug a little bite and the rpm drop also. When i down shift in my garage, i have to downshift 2 speed, not one, and i do not shift the second speed...


each time the second.
 

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u can down shift a dunable as long as u clutch first, ur supose to come to a complete stop on a true overide before u down shift.
but not on a dunable, just dont backload it
 

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There is nothing wrong with your tranny per say. It's the shift star most likely. It has been ground too short on its points and is rolling through on its own because of the vibration. all you need to do is get another shift star from wcr. not the first i've seen from there do that.

there is no difference in the cut of a duneable, to a regular override (side by side comparison). the only difference is the springs, as long as you don't back load a override you can down shift em. I do mine and have never screwed up anything from it.
 

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What do those 3 springs do in a dunable. It seems like they help the forks slide into place. But it doesnt look like the spring generate a lot of force. But that's my guess. I have a n-down 5 dunable. Just curious. I was told i can backload it but not above 8k rpms. So far so good. Although i have less than 4 hours on it and i baby it.
 

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QUOTE (nemesis @ May 17 2009, 11:09 PM) index.php?act=findpost&pid=43047there is no difference in the cut of a duneable, to a regular override (side by side comparison). the only difference is the springs, as long as you don't back load a override you can down shift em. I do mine and have never screwed up anything from it.

While that could be true for some folks that cut trannys, for WCR it isn't.
The gears are cut identically...but the drum on a dunable vs. the drum on a standard override is cut different.

I run a 1-5 N down dunable WCR tranny as well, and have seen a std. cut drum...it is different.

The shift star doesn't have to be rounded at all for an override, just cut and welded.
 

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QUOTE (dajogejr @ May 18 2009, 05:44 AM) index.php?act=findpost&pid=43064While that could be true for some folks that cut trannys, for WCR it isn't.
The gears are cut identically...but the drum on a dunable vs. the drum on a standard override is cut different.

I run a 1-5 N down dunable WCR tranny as well, and have seen a std. cut drum...it is different.

The shift star doesn't have to be rounded at all for an override, just cut and welded.

you are correct about the drum, but the gears remain the same. the gear is what determines if it can be backloaded or not, because of the ramps. i.e. no difference. you are correct the shift star doesnt have to be rounded, but for the neutral down, the neutral posistion of the star has to be built up and reground, which is where his problem will be. it is too short and rolling past it.
 

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the neutral point on the star shouldn't have anything to do with it shifting gears

if the neutral point wasn't right it just wouldn't stay in neutral it would try jumping into gear when pushing is around or with it running in neutral
 

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QUOTE (SANDPLAYAZ @ May 18 2009, 10:00 AM) index.php?act=findpost&pid=43105the neutral point on the star shouldn't have anything to do with it shifting gears

if the neutral point wasn't right it just wouldn't stay in neutral it would try jumping into gear when pushing is around or with it running in neutral


Its a neutral down tranny so it has everything to do with it jumping gears from first to second.
 

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if its a neutral down then neutral is blow 1st there for a 1st to 2nd jump shouldn't have anything to do with the neutral? if neutral was still between 1st and 2nd i could see then!

the neutral is on the notched point on the star with a neutral down it will be in neutral on the notched point then will go to 1st gear in the next dip then over the next whole point to 2nd gear in the next dip if your point where neutral used to be between 1st and 2nd is still notched it will affect it it should be built back up to match the other points and the new neutral down should be notched

on a reg neutral set up, the noched point is between 1st gear and 2nd on a neutral down it is not there fore it would not have any affect of it jumping from 1st to 2nd
 

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Discussion Starter · #15 ·
Thank for all the information.

Yes, new shift fork, shift like butter, even too smooth...


today my track was better, i try it and seem to run very very ....very faster than my stock tranny.

I try it today and the tranny seem to work very well. Don't shift by herself.
 

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QUOTE (SANDPLAYAZ @ May 18 2009, 01:01 PM) index.php?act=findpost&pid=43154if its a neutral down then neutral is blow 1st there for a 1st to 2nd jump shouldn't have anything to do with the neutral? if neutral was still between 1st and 2nd i could see then!

the neutral is on the notched point on the star with a neutral down it will be in neutral on the notched point then will go to 1st gear in the next dip then over the next whole point to 2nd gear in the next dip if your point where neutral used to be between 1st and 2nd is still notched it will affect it it should be built back up to match the other points and the new neutral down should be notched

on a reg neutral set up, the noched point is between 1st gear and 2nd on a neutral down it is not there fore it would not have any affect of it jumping from 1st to 2nd


exactly, now you are understanding what i was talking about. the point wasn't built up and it rolled over it into second on it's own. I have personally owned one from them that I had to replace the shift star because of this issue. Not a big deal I was just trying to help him out with what to look for.
 
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