Another Borg Warner VD question

I have a VD question, but first I will give a little back story.


34 Californian LRC, twin Perkins with turbo's and VD transmissions. I'm losing fluid in one of my transmissions ¼ quart in 6 months. After inspection I could not locate any points of interest for leaking (seals, plugs, linkage entry points, etc), everything looks pretty clean and free from signs of leakage. I spoke to the PO, who is a great guy and was anal about all mechanics on the boat; he indicated he replaced the cooler right before I purchased the boat. He also said he never had to add fluid to either of the transmissions but regularly checked. This transmission was replaced with a new old stock unit less than 4 years ago. All high pressure lines were professionally made and replaced. I did have some fluid in my bilges but it could be from a bad line on my trim tabs (the reservoir was low on fluid and a line was leaking). Also, each engine transmission combo in my boat has containment pans which will not allow fluids to leak into the bilge in the event of fluid loss.


I could accept if the PO changed out the unit less than 4 years ago and never had to top off fluid, that the newly placed transmission cooler is the prime suspect, albeit, the cooler, lines, fittings, something. I could also easily explain the fluid in my bilge from the trim tab line failure (which has been repaired).


Where is my fluid going?


Thanks for the help!

Do you see oil sheen from the exhaust? I had a leaking cooler and the first thing we (actually my wife) noticed was a slight oil sheen from the exhaust. Of course with diesel that may be impossible to tell. Bottom line is that we've had coolers leak a couple of times, always into the cooling water. The good news is that the pressure is so high that the net flow is oil into the cooler rather than water into the reverse gear.

If it were me and there were no external leaks, I'd change the cooler again and see if that fixes it. You could then have the one that's suspect tested and repaired as a spare.

It's going out in the cooling water via the oil cooler or its dripping into the bilge. No other places for it to go.

Thanks, to both comments. The PO and I feel the same and suspect a failed cooler. I will swap it out and go from there.

Lay down white oil sorbent sheets under the trans, bell housing, cooler and around your trim tab lines and look for the leaks. Put them under the engine oil pan too.
A bale of 100 is like $30 on Amazon.

High Wire said:

Lay down white oil sorbent sheets under the trans, bell housing, cooler and around your trim tab lines and look for the leaks. Put them under the engine oil pan too.
A bale of 100 is like $30 on Amazon.

Click to expand...

I actually run them, there was some pinkish tone after six month but wouldn’t equal to 1-4 quart. I ran it today for a few hours and I had zero signs of any fluid under any portions of engine or tranny.

Thanks for the tip!

Many years ago, like 40+ I replaced a BorgWarner velvet drive in my Chris Craft, it came with oil cooler attached, easy job, hook it up and go, 4 months later no oil, no drive, lesson learnt make up fitting for zinc as cooler did not have one, expensive lesson for new Commercial Captain, learnt a lot since then, and still learning at 70+

The VD oil lines are not HP. But, enough to push out thru the cooler when underway.
U are likely using ATF, which, of course is the same color as your trim system leaker.
Really, 3 likely points of VD oil exit. Output shaft oil seal, input shaft oil seal, and the cooler. More rarely, the spool F-N-R shaft. Pretty easy to test the cooler; plug one oil fitting, pump in 10 psi air into the other, and hold the thing underwater.

Rule #1: do not run the VD with low oil, especially important if you have no pressure gauge. It will trash the clutches in short order.

Thanks everyone for the tips and information, here’s an update...

After backing the boat in the slip the other day I went down this morning and ran her to temp. Knowing being backed into a slip would contain top water for better sheen observations I went and had a look.

There is definitely a sheen on the water, noticeable but not to the point of brining in a hazmat rig but it’s there and even with a diesel I think it is more than what should be there. I’m at the 98% opinion that the cooler has failed. I will remove and send back to Mr Cool for a test and replacement. See pictures.