NXT transmission / drive question
#1
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Joined: Feb 2021
Posts: 8
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From: NJ
Been searching the forums and haven’t found any recent feedback on the NXT drive. Looking to purchase a 39’ Cig TG with 700s(worked to 850hp) and NXT drives. Cobellas rebuilt the drives at 300 hrs, but he did not touch the trannies. Boat now has 430 hours on it, and previous two owners have not touched the transmissions (they owned since 275 hrs). Is it possible the transmissions could be original? Owner said it takes a little force to get the boat in and out of gear. That makes me believe both transmissions are shot. What do you guys think?
#3
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Joined: Jul 2008
Posts: 588
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From what I’ve experienced, I would have rebuilt the trannies before the drives. The weak link in the NXT package is the tranny before the drives.
I’ve put a lot of very hard hours on a twin staggered 700/NXT package spinning Merc 5 blade cleavers. Always serviced the oil in the trannies 1-2 times per year and it was always semi dark and I could tell it was a good idea to change the oil once it was draining. Out of 3 years of abuse, I only changed the drive oil one time and from visual, smell, and inspecting the oil by hand for metal particles it seemed normal and not burnt up or anything bad. 2 years into that 3 years no matter the amount of maintenance of oil changes I did, one of the trannies blew up. When I say blew up, it didn’t just smoke a clutch or break a couple teeth on the gears. It broke the tranny housing in multiple places and was scrap metal needing a full tranny replacement.
I’ve put a lot of very hard hours on a twin staggered 700/NXT package spinning Merc 5 blade cleavers. Always serviced the oil in the trannies 1-2 times per year and it was always semi dark and I could tell it was a good idea to change the oil once it was draining. Out of 3 years of abuse, I only changed the drive oil one time and from visual, smell, and inspecting the oil by hand for metal particles it seemed normal and not burnt up or anything bad. 2 years into that 3 years no matter the amount of maintenance of oil changes I did, one of the trannies blew up. When I say blew up, it didn’t just smoke a clutch or break a couple teeth on the gears. It broke the tranny housing in multiple places and was scrap metal needing a full tranny replacement.
#4
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Joined: Jun 2011
Posts: 2,169
Likes: 82
From: Henderson, KY
I had a difficult to shift trans once, but it ended up being a cable issue - took both hands to get trans into neutral. So had all cables replaced. After that, both shifted like butter.
2nd time I had a problem, the trans shift mechanism broke at Destin PR in Destin Harbor. Fortunately, the trans stuck in forward, so we just beached it and enjoyed the day. The next morning pulling it back into Legendary (with the wind) was scary - fortunately, some friends happened to be there on the dock to help me get it tied up (was by myself).
As above, everytime I changed trans fluid (25 hour intervals), it was very dark. I use Amsoil in all of my mechanicals, and drive lube and engine oil never got dark.
If I had to do it all over again, I would have just kept a backup trans in the case it broke. Unfortunately, I don't have large enough facilities to pull the motor to swap it.
...sold the boat in September and went to outboards!
2nd time I had a problem, the trans shift mechanism broke at Destin PR in Destin Harbor. Fortunately, the trans stuck in forward, so we just beached it and enjoyed the day. The next morning pulling it back into Legendary (with the wind) was scary - fortunately, some friends happened to be there on the dock to help me get it tied up (was by myself).
As above, everytime I changed trans fluid (25 hour intervals), it was very dark. I use Amsoil in all of my mechanicals, and drive lube and engine oil never got dark.
If I had to do it all over again, I would have just kept a backup trans in the case it broke. Unfortunately, I don't have large enough facilities to pull the motor to swap it.
...sold the boat in September and went to outboards!
#7
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Joined: Sep 2013
Posts: 2,320
Likes: 1,040
From: Wisconsin
With that kind of power I’d be looking into BAMs upgrades for more worry free boating. https://www.cyborgtransmissions.com/...ts/Cyborg-NEXT




