New boat with a hot Tranny...borg warner velvet drive Q
Posted: Fri Jun 05, 2015 7:21 pm
Friends,
We are running our new-to-us Troller from Bellingham to South East and having to back off the power to keep the gear under 190 degrees which is the max indicated in the manual for it that I downloaded. The result is that we hover around a 5 knot cruise…lots of time to think!
I have a Borg Warner 71c (2.91-1) attached to a 60hp Isuzu c-240 on a 30’ fiberglass Monterey Clipper (Monterey Boat Works). The motor is cooled with a keel cooler. The transmission is cooled using a heat exchanger (about the size of a pepsi can). Because the heat exchanger is running engine coolant through it, it is clear that the gear is not going to be less than the engine (170 degrees) giving me only a 20 degree difference between engine operating temp (170 degrees) and max gear temp (190 degrees).
I have spoken to a pro trucker that I know and he says that gear over temp for them is about 220 degrees…But the Borg manual clearly states 190 …argh..
I have read on the internets that synthetic oil makes the Borg Warner slip so switching does not seem to a slipperier oil does not seem like an option. The manual indicates ATF of 30 weight are both fine…The fishermen I have spoken to all seem to prefer 30 wt.
My first thought for remedy is to try a larger cooler (heat exchanger)…they can’t come much smaller than the one that I have…but I would be very interested to hear from those with better thoughts and more experience.
Thanks for your consideration
Dave
F/V Addie L
We are running our new-to-us Troller from Bellingham to South East and having to back off the power to keep the gear under 190 degrees which is the max indicated in the manual for it that I downloaded. The result is that we hover around a 5 knot cruise…lots of time to think!
I have a Borg Warner 71c (2.91-1) attached to a 60hp Isuzu c-240 on a 30’ fiberglass Monterey Clipper (Monterey Boat Works). The motor is cooled with a keel cooler. The transmission is cooled using a heat exchanger (about the size of a pepsi can). Because the heat exchanger is running engine coolant through it, it is clear that the gear is not going to be less than the engine (170 degrees) giving me only a 20 degree difference between engine operating temp (170 degrees) and max gear temp (190 degrees).
I have spoken to a pro trucker that I know and he says that gear over temp for them is about 220 degrees…But the Borg manual clearly states 190 …argh..
I have read on the internets that synthetic oil makes the Borg Warner slip so switching does not seem to a slipperier oil does not seem like an option. The manual indicates ATF of 30 weight are both fine…The fishermen I have spoken to all seem to prefer 30 wt.
My first thought for remedy is to try a larger cooler (heat exchanger)…they can’t come much smaller than the one that I have…but I would be very interested to hear from those with better thoughts and more experience.
Thanks for your consideration
Dave
F/V Addie L