Bump and Grind Posted July 17, 2019 Report Share Posted July 17, 2019 I have a BMC 1.5 married to a 71C Velvet Drive with a problem. The oil (ATF) is up to the mark on the dipstick but when I get to about 1500rpm oil comes out of the breather. Reducing revs stops this. Has anyone got any idea what is wrong and how can I solve it. Link to comment Share on other sites More sharing options...
Tony Brooks Posted July 17, 2019 Report Share Posted July 17, 2019 Is the gearbox oil cooler connected and properly cooled with cool water flow? Never heard of this before but if its raw water cooled heat exchanger on the pressure side of the pump has the oil gone pink. If so then maybe the oil cooler is holed. Overfilling so the oil aerates might cause then but you say the level is correct. The thing I can't remember is if the level is with the plug screwed in or just lodged on the top of the hole. 1 Link to comment Share on other sites More sharing options...
Bump and Grind Posted July 17, 2019 Author Report Share Posted July 17, 2019 26 minutes ago, Tony Brooks said: Is the gearbox oil cooler connected and properly cooled with cool water flow? Never heard of this before but if its raw water cooled heat exchanger on the pressure side of the pump has the oil gone pink. If so then maybe the oil cooler is holed. Overfilling so the oil aerates might cause then but you say the level is correct. The thing I can't remember is if the level is with the plug screwed in or just lodged on the top of the hole. Oil cooler is connected and cooled by the skin tanks, no leaks or holes. Oil is ATF so is red anyway. The dipstick is not a screw it’s a plug, it’s not original, so I’m not sure if it is even correct. Link to comment Share on other sites More sharing options...
Tony Brooks Posted July 17, 2019 Report Share Posted July 17, 2019 1 hour ago, Bump and Grind said: Oil cooler is connected and cooled by the skin tanks, no leaks or holes. Oil is ATF so is red anyway. The dipstick is not a screw it’s a plug, it’s not original, so I’m not sure if it is even correct. Yes. Velvetdrive dip sticks are on the end of what looks like an iron plumbers male blanking plug with a square to put the spanner on. I did not ask you if the oil was red, I asked if it was punk and that indicatives water contamination. Not sure how you can be so sure the oil cooler core is not leaking because that would not show on the outside but would show as pink (not red) oil or pinky oil in the engine header tank. Link to comment Share on other sites More sharing options...
steamraiser2 Posted July 17, 2019 Report Share Posted July 17, 2019 Are you sure that you have the correct dipstick? Only ever seen a similar thing when a gearbox was overfull Link to comment Share on other sites More sharing options...
Tony Brooks Posted July 17, 2019 Report Share Posted July 17, 2019 5 minutes ago, steamraiser2 said: Are you sure that you have the correct dipstick? Only ever seen a similar thing when a gearbox was overfull Not sure how to tell if its correct. The OP may very well have a reduction box on the end of the gearbox but I thought they all used the same oil. If it is separate then there is a good chance the dipsticks have been transposed Lister style. Link to comment Share on other sites More sharing options...
Bump and Grind Posted July 17, 2019 Author Report Share Posted July 17, 2019 I don’t see any trace of water in box or oil in the cooling system. The box (I believe) is quite early, the serial number is 7716, so the dipstick might be sortoff original. Someone else mentioned overfilling so I will take some oil out and retry this weekend. Link to comment Share on other sites More sharing options...
john.k Posted July 18, 2019 Report Share Posted July 18, 2019 The Velvet drive is also used with a torque converter,and for some reason some blow oil out the filler /breather....cure is to install a large capacity catch can ................Dexron can assume a pink colour when its aerated................with water its a very anaemic pink like a blancmange.....a pink one ...... Link to comment Share on other sites More sharing options...
Tony Brooks Posted July 19, 2019 Report Share Posted July 19, 2019 20 hours ago, john.k said: The Velvet drive is also used with a torque converter,and for some reason some blow oil out the filler /breather....cure is to install a large capacity catch can ................Dexron can assume a pink colour when its aerated................with water its a very anaemic pink like a blancmange.....a pink one ...... I can't say you are incorrect but I have never seen a torque converter on a UK inland boat. Borg Warner auto transmissions yes, but not with marine Velvet drives. Link to comment Share on other sites More sharing options...
john.k Posted July 19, 2019 Report Share Posted July 19, 2019 Set one up....a paddle wheeler.....or sidewheeler to be more correct.......the tractor tranny shares most parts with the marine one. Link to comment Share on other sites More sharing options...
MtB Posted July 19, 2019 Report Share Posted July 19, 2019 1 hour ago, john.k said: Set one up....a paddle wheeler.....or sidewheeler to be more correct.......the tractor tranny shares most parts with the marine one. You have a sidewheeler using Velvetdrives? Brilliant!! Got any photos?? Link to comment Share on other sites More sharing options...
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