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NXT Tranny Question

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Old 05-24-2011, 12:23 PM
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Default NXT Tranny Question

How does your tranny feel when shifted into gear? Starboard side is like silk, but the port has a slight flunk similar to the feel when you shift it by accident slightly above idle. Both transmissions are off a fresh refresh. The port had the problem prior to the rebuild and functioned fine otherwise. I have been told that the "feel" isn't adjustable but I find that hard to believe.
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Old 05-24-2011, 02:20 PM
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Chuck,
You sure it's the tranny causing the 'thunk' ?
Seems like not much in them to cause that issue. Do both drives seem to have the same amount of backlash at the prop-shaft ?
I had an engine shifting rougher than the other, found gearsets in the drives that were mis-matched sets.

Am sure you checked, but is your shift cable adjusted to get the linkage fully into F-N-R ?
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Old 05-24-2011, 02:28 PM
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I will have to look into a cable adjustment. Gear sets have never been changed and this problem is only from sometime last season to present. If I'm going into forward and reverse can there still be a cable adjustment issue? Thanks Kelly.
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Old 05-24-2011, 02:29 PM
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Dont mean to sound stupid but what is backlash at the propshaft, and how is that measured?
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Old 05-24-2011, 03:57 PM
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92 views and only one response. Where are all the techs???
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Old 05-24-2011, 04:19 PM
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Chuck,
Pull and push in on the prop shaft,the movement you fell is what is called "Back Lash". Too much backlash is an indicator that propshaft needs attention.
Hope this helps.
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Old 05-24-2011, 05:56 PM
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Originally Posted by Dean Ferry View Post
Chuck,
Pull and push in on the prop shaft,the movement you fell is what is called "Back Lash". Too much backlash is an indicator that propshaft needs attention.
Hope this helps.
Dean
Thanks Dean
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Old 05-24-2011, 05:58 PM
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Dont mean to sound stupid but what is backlash at the propshaft, and how is that measured?
Referring to backlash of the drive gears, measured in thousandths, which translates into freeplay in the rotation of the propshaft.
When you manually rotate the props back and forth, does one shaft have more free travel than the other ? In your case the port drive would have more free travel if backlash is not correct. This would cause the thud going in and out of gear.
I ask this knowing you had a propshaft issue once, and setting up the lower unit when replacing the shaft would need to be done correctly.
Other than that u-joints would be another suspect, depending how much trim you run causing excessive wear.
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Old 05-24-2011, 06:01 PM
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Originally Posted by Chuck View Post
I will have to look into a cable adjustment. Gear sets have never been changed and this problem is only from sometime last season to present. If I'm going into forward and reverse can there still be a cable adjustment issue? Thanks Kelly.
I think the biggest danger of a mis-adjusted cable that does not shift completely into forward is burning up the transmission due to slippage, have to check the service manual again.
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Old 05-24-2011, 07:06 PM
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Quote:
Originally Posted by Kelly O View Post
Referring to backlash of the drive gears, measured in thousandths, which translates into freeplay in the rotation of the propshaft.
When you manually rotate the props back and forth, does one shaft have more free travel than the other ? In your case the port drive would have more free travel if backlash is not correct. This would cause the thud going in and out of gear.
I ask this knowing you had a propshaft issue once, and setting up the lower unit when replacing the shaft would need to be done correctly.
Other than that u-joints would be another suspect, depending how much trim you run causing excessive wear.
KO,
Thanks for the clarification, Chuck good luck with this issue.
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