Transmission toast?

My transmission started slipping badly yesterday while wakeboarding with a heavy load. Fluid level was full, and the issue persisted after I added even more ATF. Had to idle back to the dock. Prop kept spinning while in neutral. When I pulled the dipstick there was a bit of smoke coming out of the hole. Clearly some major issues in there. I had the same thing happen a few years ago due to low fluid level (and I have at times noticed a very small leak from the front of the transmission). At that time filling up with ATF resolved the issue, but not this time. Engine was running at normal temps, so I don't think the oil cooler got clogged up or that the cooling system was malfunctioning in some way.

As the tranny is almost 40 years old, it doesn't owe you much.  It might be time to rebuild the Velvet and look forward to another 40 years...

I've always struggled with the idea of rebuilds on car and truck automatic transmissions. Some rebuilds or the rebuilders don't seem to be worth the effort...  while I have mastered stick shift rebuilds in recent years, I have yet to handle autos. Are there trusted resources to handle our reverse gears??

8122pbrainard wrote: wetskier2000 wrote: I've always struggled with the idea of rebuilds on car and truck automatic transmissions. Some rebuilds or the rebuilders don't seem to be worth the effort...  while I have mastered stick shift rebuilds in recent years, I have yet to handle autos. Are there trusted resources to handle our reverse gears?? Rick, You really can't compare our marine "transmissions" to auto and trucks. Think more towards a wet clutch.

FFImarine wrote: We would be more then happy to rebuild your velvet drive. Give us a call 330-273-8291

Thanks a lot Joe, I would definitely have sent it to you, but I am in South Africa, which complicates logistics ever so slightly .

So I've started disassembly. First problem is pretty obvious in the reverse clutch:

It's very common for velvet drives reverse to snap reason being it's such a large plate and it's bronze and it just takes time for them to fatigue and Crack. Google flat snap ring pliers and you'll find what your looking for as for the rings holding the forward piston in a flat head screw driver will get them out easily

Keno, snap-on makes a pair which I use and in the serated area they put a small dimple that makes grabing lock ring so much easier

I've read all of the Velvet Drive service manuals I've been able to lay my hands on, and have two questions I'm hoping someone can help me with:

FFImarine wrote: I have only replaced coupler nuts when they are severely rusted or damaged, you can flush cooler lines and the cooler it's self with brake cleaner and compressed air but if you had water intrusion then it's safe to say you'll need to replace your cooler

Question 1   The manual says to knock it out with a soft blunt tool. With your engagement and slipping issues it may have taken more effort to get it out.

So I rented an impact wrench, which did the trick to get the nut off. I put some long bolts through the coupler bolt holes and used a tyre lever wedged against a trailer wheel to hold the coupler in position while I hit it with the impact wrench. So now I finally have the entire transmission disassembled and can start cleaning everything out while I wait for parts to arrive. Didn't want to place orders before I was sure of everything I need, so that I can only suffer shipping charges once. Luckily everything except the clutch plates, reverse springs and one snap ring (that bent when I took it off) looks to be in good shape.

The manuals (and Wouter in post #49 in the TeamTalk thread I posted a link to earlier) all say that one needs a press when it comes to compressing the forward clutch pack for installing the snap ring that holds the forward clutch cylinder in place. Any reason why a C-clamp of suitable size won't be up to this job? I'm sure a press will be easier to work with, but it seems to me a large C-clamp will also get the job done?

Some aviation manuals discourage powder coating because it can hide a crack, while paint will usually show a developing crack.  Don't know if this is a concern for a transmission case.

The section of my transmission's coupling on which the rear oil seal rides seems (and feels) pretty rough - see below. The seal rode (as best I could tell when I disassembled things) on the thicker of the two black lines that are visible on the 'snout' of the coupling.