Bowman DC60-XCC Transmission Oil Cooler Failure; ZF Hurth ZF 25; Yanmar 4JH3-HTE #lessons
In the spirit of Pat from Shenanigans "Lessons Learned" post a few week's back I thought I would share what I learned when my Bowman DC60-XCC oil cooler failed while motoring up the coast of Maine a few days ago. Thankfully, we caught the failure relatively early in large part due to the fact that when cruising in Maine you have to remain hyper-aware at all times because of the lobster pots that are literally all over the place including in marked channels and anchorages. Because of that, both my wife and I were in the cockpit doing nothing but looking out for lobster pots and calling out their positions to whomever was at the helm. There were no podcasts, no music, no book reading, no headphone, just hyper-vigilance with two people, 4 eyes, and 4 ears on watch at all times.
Once we were safely moored, I went down to the engine room to check the oil in the Yanmar. It was perfect. Not a drop appeared to be missing. After a brief “wtf?” moment, I checked the transmission dipstick. The fluid level did not even register on the dipstick at all. However, I could see that there was some ATF left in the transmission case. That was a bit of a relief but not much.
All of this happened on a Saturday and I do not carry a spare oil cooler so I would have to wait until Monday to order a replacement. First thing Monday morning I started to call all of the USA dealers for Bowman marine products listed on Bowman’s website. Of those who actually answered the phone, none of them had the DC60-XCC in stock or even just the DC60 (oil cooler with no end caps). One actually told me that he didn't think DC60-XCC was a valid Bowman part number. I said “I’m looking at their catalog online right now. It is.”
I then called Bowman in the UK and asked if they knew anyone in the USA who might have one of these in stock and they hesitated and said the only one who might have one is Tradewinds Power Corporation. When I had previously called Tradewinds Power Corporation they said "our computer system is down right now" so we will need to call you back. They never did.
Luckily, I had also asked Bowman who in the UK would definitely have them in stock and would ship to the USA. Without hesitation, they told me that Lancing Marine will definitely have it and they ship around the world. So I called Lancing Marine (https://www.lancingmarine.com/) and had a wonderful experience buying from them. Not only were their prices the lowest by far that I had seen anywhere online (79 GBP/~109 USD including new couplers) but the ordering experience was fantastic despite it being phone order only. The person I spoke to also obviously knows these transmissions well. His name was Mike and I'm pretty sure he is the owner and founder of the company - founded in 1970! He gave me his opinion on the state of my transmission (he thinks it’s probably fine) and advice on how to test it to see even before the replacement cooler arrives. On top of all that, despite it being about 3pm their time when I called, the coolers (I ordered a spare) shipped out the same day. Last, he said that if I do need to get the transmission rebuilt, that he would highly recommend a company in the lower Chesapeake Bay called Transatlantic Diesels. He says that they know these ZF transmissions better than anyone and he has done business with them for years. It was really just a great overall buying experience that seems to be so rare in these days of anonymous Amazon purchases.
The moral of the story is that for ~$109 plus shipping and an hour of my time I should have replaced the transmission oil cooler PROACTIVELY soon after I bought the boat back in July 2017. Especially given that I did not know the age of this critical part. Or I should have replaced one of four times that I have replaced the transmission fluid. At the bare minimum, I should have had a spare oil cooler already on board. The engine, and I assume the oil cooler, just surpassed the 2000 hour mark. Researching this site after the fact I found at least two other SM owners who had the same failure at around the 2000 hour mark. Both, I believe, lost their transmissions. Hopefully, I have not. I will know in a few days time.
So in the spirit of the #lessonslearned, don’t be like me. If you are not sure how old your transmission oil cooler is, replace it. If it’s approaching 2000 hours, replace it. At a minimum, get yourself a spare oil cooler. And if you can’t find it locally, get it from the nice people at Lancing Marine in the UK so that we all have at least one place in the world that keeps these things in stock.
SM #440 Cara
Belfast, ME USA