Boat is 28 Sports Express with twin late model Crusader 5.7, VelvetDrive 1:1 trans. A couple weeks ago on the way home from a short run, the port tach ran up high and power dropped. Pulled throttles to idle, shifted to neutral. Shifted Port to forward with some gas, nothing. Shut down engine and limped home on starboard. At the dock, trans fluid sprayed around, dipstick laying loose, almost no fluid in it. Brown water under the engine.
A few days later, sucked out all fluid and refilled it. All was okay till last Sunday, out with a prospective buyer, and it did it again but the dipstick stayed in. No water under engine, but a few days later there was some. Vacuumed it up and put paper towels underneath, no wet spots. Sucked out the trans and got 1-1/4 quarts of brown fluid. (should be 2 quarts of red fluid.)
So, it seems to me the likely culprit is the trans cooler leaking water into the transmission fluid, and trans fluid leaking out to the exhaust stream until there’s not enough fluid to run the transmission. Make sense?
I would think you would want to flush out transmission a couple times with fresh fluid anyway, so may as well install a new cooler when in is empty.
Pulled cooler today and applied air pressure to the transmission fluid side. So far it’s holding. Strange thing though: there were bits of rubber (I assume impeller bits) in the water side. Not sure how, as the cooler is upstream from the seawater pump.
The cooler lost some pressure over a few days, so I’ve decided to just replace it. I figure there can’t be any place else where water and trans fluid could mix, and it probably leaks more when it’s warmed up.
Just replaced one in a 30 TSF last week. Got the replacement from Mrcool.us exact replacement 1/2 the price.
Also this one we did fell apart and all the fluid went out of the exhaust. Just for diag. Did you see any sheen? When you put the new one in you may still see a sheen for a bit as the lost fluid gets out of the muffler. Hope this helps
Got a factory replacement from marine parts source .com. Put it in and first test seemed ok at speed, but coming back into my slip it’s sluggish to shift into forward at idle. Bump the throttle a bit and it shifts. Fluid is right at the full mark. Reverse works fine. Any ideas?
I had a similar problem on a velvet drive before where it wouldn't shift unless I throttled up .
It turned out to be some bronze bushings in the trany were worn causing a lack of pressure which is needed to stay engaged in gear
That’s what I’m afraid of. It’s possible that the first time this happened a few weeks ago, I didn’t shut the engine down quick enough and some damage happened.