71C Velvet Drive --- Reverse Blew.... AGAIN! -- Where to Exchange?

[Luv2Ski]

Hi all,

Bought and restored the boat in the 2009/2010 winter. When I purchased her the transmission had a blown reverse gear.

I rebuilt the transmission. Aside from the reverse clutch disks (which were fractured in several places), transmission looked great internally. After rebuild, I did have some neutral creep (despite having set the gap on the forward clutch pack) which always bothered me but I opted to live with for the season in hopes that it would go away after the clutches broke-in.

Fast forward to this weekend. Second outing of the season (~ 60 hrs on rebuild). I am cruising down the lake at about 3300 RPM for maybe 15 minutes and then decided to open it up for about 30 seconds before brining it down to an idle to prepare for docking. While pulling the throttle back I can begin to hear a horrible whine from the transmission (wife who was sitting in the rear said it started just before I backed off the throttle). I shut it down. Took out the dipstick, plenty of good-looking ATF, but also heat and some smoke.

Started it back up, whine continued, forward felt great, reverse.... GONE. Drove to a friends dock and parked. Several hours later, I drove the boat back to the marina, whine was gone, but so was reverse.

Pretty certain based on symptoms that the reverse clutches/springs are toast again. Would say the whine was caused by the springs or clutches and now they have settled in some way that they are no longer dragging.

Yes, the shift linkage is fine.

Questions:

1. Why would reverse blow more than once. Even more strange, what caused it to blow while moving forward? Perhaps something is wrong with the regulator (pressure too high) or the selector valve itself. This allowed reverse to be engaged while in forward? Maybe I just got a bad clutch disk that came apart at high velocity.... but then there is the fact that they were broke when I bought the transmission....
2. While rebuilding again would certainly be the least expensive, I am concerned that I am treating the symptom and completely missing the root-cause. As such, anybody know where I can swap this core for a rebuilt unit at a reasonable cost?

88 ProStar 190, 351 attached to the 1:1 71c Velvet Drive.