Borg Warner Velvet Drive Questions

About a week ago, after a 10 hour run, I found an oil leak at the rear of my port marine gear. It appears to be coming from the center of the yoke, which is puzzling. A quick look at the output yoke seal, cooler lines and rear housing gasket did not show a leak. Has anyone had a problem like this? Also- I'm pretty sure I have a 1:1 tranny, but can only find a SN tag. Any help here on identifying quick model I have?

Oil can leak past the splines on the yoke. Could that be what you are seeing?
You are supposed to coat the splines with RTV when you put it together....not in the manual, but an old time rebuilder told me that.
You can look up your local BW distributor on line and call them...they will be able to identify your tranny model.
I've worked with the dist in Rowley, Ma and they were always very helpful.

Thanks. Just what I needed to know.

The rear cover of the transmission contains an oil seal that seals against the output flange. It's not uncommon to have this seal leak and it's no big deal to replace assuming you have a puller strong enough to pull the flange. When re-assembling the book recommends torquing the nut to something like 250lbs, but many re-builders simply use an air operated impact. I did my first one that way and it developed a leak, while I used a torque wrench on the second one and it never leaked. It can either be replaced in place, or you could pull the back half of the transmission and take it to a shop for repair. All in all it shouldn't take more than a few hours..........Arctic Traveller

Like Arctic we developed a lubricant leak out the back end of one of our Velvet Drives a number of years ago. It didn't leak a lot but the giveaway was a thin line of fluid up the side of the adjacent fuel tank where the spinning shaft coupler threw it. The diesel shop we used changed the seal in situ in a fairly short time. Disconnected the shaft, slid it back a bit, removed whatever they had to remove to get the old seal out and the new seal in, slid the shaft forward, checked the alignment (I don't know if they had to make any adjustments to this or not) and reconnected the shaft.

Follow up

Another forum that I participate in has really been encouraging participants to follow up on technical questions with final result. Thought I would do the same here. Notice the grey storage tub in mg origijnal picture. I put funnels, small drain pans, etc. in there. Usually they are still dripping motor oil. Turns out the tub slid over the flange during the voyage and it rubbed an unnoticed hole in the bottom......?

Nice fix, wish they were all that easy.

I recently had the port seal replaced, quite a job. As per one post above, the first sign is a fine spray ejected at the coupling, noted by my mechanical surveyor at purchase. At that stage replacement is indicated but not urgent.The mechanic made a point of realigning engine and shaft. I discovered well post purchase, history that engine picked up a rope on the shaft, causing damage.

Hard to tell from picture but I believe it is CR2 series(DROP CENTER). Tag should be forward of shift lever,dipstick.Just guessing about tranny.Nice to see you solved your problem.

Thanks Iceberg. Turned out they were drop centers.

These transmissions are known for excess wear on the output coupling flange splines. Remove flange (and replace seal), inspect splines for wear, replace coupling if necessary and use loctite retaining compound in the splines to take up any slight wear remaining.