Gear cooler

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toddlvogel

Member
Joined
Sep 9, 2016
Messages
9
Location
United States
I had an unfortunate accident last summer, running over a submerged rock. I had to replace all the running gear and my tranny. This boat is a 2007 MS 400 with a single Yanmar 6LY, ~ 400 eng. hrs. My boat yard says they were surprised that I didn't replace the gear cooler with the tranny and I should do it now. $1100!
I would greatly appreciate any/all advice. I see only a little bit of leakage at the hose joint which was present before the accident.

Thanks, Todd Vogel
 
At 10 years old, I would consider replacing it if it original. $1100 seems pretty high. One for my lehmans runs several hundred dollars.
 
Your original cooler must ne copper/nickel otherwise it would have filled your new transmission with water by now. I agree it's time for a changout and that $1100. is high..
 
I would join Boatdiesel.com and ask there how long your gear cooler should last before throwing money at something that may be good for several (many?) more years.
 
FWIW.......I have a Kanzaki gear hooked to my Yanmar 4LH The Gear cooler is internal. Had it out last year when I had the gear rebuilt. The cooler looked like new. Both the Yanmar and Kanzaki are vintage 1991 with 1700 hours consistently in salt water.
 
Yanmar parts are often three times the cost of after market parts. That gear cooler is generic and one from Lenco, Bowman, etc should work if the dimensions are similar. Do get one with cupro-nickel tubes.

David
 
I dont see the connection between hitting something and the gear cooler.

Does the cooler use sea water of engine coolant? IMO that will make a big difference in life.
 
The Yanmar 6LY and all other marine engines I am familiar with, use a sea water cooled gear cooler. Ten years is getting to the end of their life in sea water service, particularly with copper tubes.

David
 
I dont see the connection between hitting something and the gear cooler.

Does the cooler use sea water of engine coolant? IMO that will make a big difference in life.

The shop would be worried about metal bits from the tranny, due to the collision. Very few shops would willy nilly put a new tranny in there with a cooler known to have been connected to an accident damaged tranny.

And, certainly replace at 10 years, if just copper, even without damage history.
 
Dave:
If that were the case then why not flush the cooler?. In fact they should flush everything in the system.
 
Dave:
If that were the case then why not flush the cooler?. In fact they should flush everything in the system.

That would reduce, but no eliminate the risk. Funny this comes up now. I just had my minivan auto transmission rebuilt, and they demanded to put on a new ATF cooler! They even bypassed the rad built in cooler...
There is no way 3 to $6k jobs will be risked by a dirty cooler that is un-inspectable.
 
If you replace with a generic cooler, be sure you know whether it's on the low pressure return or the high pressure side of the oil system. That will affect the required pressure rating for the cooler.
 
Interesting thread.

I have 2005 yanmar 4lha-stps in my boat with the original gear coolers. They have never given me any sort of issues, my transmission fluid is always in perfect shape. But this thread worried me a little, so I called my yanmar certified dealer and asked him if I should be concerned.

His suggestion was to pull them and take them to a good radiator shop to have them cleaned and pressure tested.

New ones for my motors are $285.
 
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