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Discussion Starter · #1 ·
I am looking for some info/opinions concerning override trannies.
I have a 1-5 (no 6th) neutral down. It is supposed to be a duneable. It has three springs on the rear shaft, one on each end between the forks and the cases and one between the forks.
It eats shift forks.

After only a dozen or so passes, it galls the forks between the gears so badly that it will not shift reliably under pressure. It will still shift fine when just casually riding. I have already replaced them twice and need to do it again.
Is there something I can do to cure this, or, do I need to just get a "real" override?
Any input at all will be greatly appreciated!

Thanks,
Rick
 

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No that should shift fine. A 1-5 duneable should be a good tranny and let you ride as you want just as long as you dont backload it really hard too much. Dont downshift hard to slow down or anything. Might be out of whack somewhere.
 

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I have the same tranny, put used forks in it when I built my 10 mil cub over 2 years ago, still on the same set of forks (Just torn down and inspected over the winter) and they look fine. I have hundreds and hundreds of passes on mine.

Is this the dunable you got from HJR? I talked to Kevin with about a customer of his with a similar problem.
IF so...I talked to him and told him I'd ask to see the cases as well.
I think you might have PM'd me about this on HQ as well...

There are guys that use dunables in TT races (full throttle, off the gas, etc. for laps and laps) that only replace the shift forks once a year.....

I can see one set if the fork set was questionable...but I think you said the forks were new. Hell..you should get years worth of passes out of them...
 

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I will inspect everything and make sure nothing was overlooked. I'm going to swap out the whole trans for you when I get it. If your cases are true you should have no problems. We will get this problem fixed for you. Your next problem will be trying to hold on to a drag ported 421 on alky. Ask David about that.
 

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Discussion Starter · #5 ·
I tore it down and sent it to Kevin. He should get it today or tomorrow. The forks were not as bad as I thought they would be this time. I sent them with the tranny so he could have a look.
My problem from the start is that, after a half dozen passes, it begins to not want to shift. The shifter moves but nothing happens. Once it starts, it gets progressively worse. I went to the Battle of the States race at Andy's last month and only got 2-3 passes where it shifted properly.

This is the first I've heard about cases.
How do I check to see if that is the problem?
Do y'all think that eating the forks is the problem?
Or, am I tearing them up trying to get it to shift?
Could it be the clutch? Several people told me over rides won't shift if the clutch is slipping. I am running a slingshot with all the bawls, new fibers, steels, & springs.
Since I first put the cub on it, I have had h3ll getting it to shift reliably. Everything except the cases is new.


A BIG thanks to Kevin, I really appreciate his efforts.



Your next problem will be trying to hold on to a drag ported 421 on alky.
 

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This could be way beneath the problem you are having? but make sure your shifter cam bolt is adjusted correctly, so you are getting a full click out of your shift shaft, and on a drag bike you can cheat it a little towards upshifting, since downshifting is not as important. If the pawl does not click back all the way, it will stop turning the drum.
 

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Discussion Starter · #8 ·
Yes, I have adjusted and readjusted the cammed bolt many times, trying to figure this out.
Kevin is going to swap the tranny out and I have a new shift shaft coming (along with all the clips, keepers, retainers, bearings, and even a new idler gear). I see nothing obviously wrong with any of these things, but I ain't takin any chances this time.

Thanks,
Rick
 
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