Re: Stus-List Transmission ratio for LF38
Thanks for the replies and info. Sorry, don't get on email much at the moment. Finally determined that the existing 2.13:1 forward ratio appears to be correct. I found an old post from Wal that had a prop calculator attached. Ran the specs, and the gearbox ratio seems to check out for our 2 blade prop pitch and diameter. I always thought the prop looked a bit small, and the owners manual shows and 18" prop with the 2.8:1 ratio - I guess at one stage they were spinning the bigger prop a bit slower. We'll stick with the current setup - one step at a time. I managed to find a new gearbox in stock at Foley Engines (Dr Diesel) and it's currently in transit to Fiji. There were also 3 available on eBay at fredwarner1.net but he wasn't able to ship to Fiji. Quite a relief to get one because the lead time from Australia was 17 weeks! We are still in Fiji awaiting the gearbox before heading back to Australia at the beginning of November. We have been in here for 3 years now with summer storage in a cyclone pit at Vuda Marina. We got through Cyclone Winston unscathed although very stressful at the time because we couldn't get back here to baby sit. My heart goes out to all those people who weren't so lucky and are suffering in the Caribbean. It must seem never-ending in that part of the world! It will be good to get out there again after a long stint of work. Tony Mitchell SV Irish Melody, 1983 LF38 #150 Vuda, Fiji ___ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated!
Re: Stus-List Transmission ratio for LF38
Tony, >From my Yanmar Service Manual, Marine Diesel Engine, Model 3QM30(H), Chapter 1 >General, 2. Specifications: Reduction gear system Reduction ratio: Model: 3QM303QM30H3QM30Y3QM30F ModelYP-10MKH-18YP-10MKH-18 Reduction Ratio: Ahead2.20/3.212.31/3.002.20/3.212.31/3.00 Astern2.30/3.461.96/3.062.30/3.461.96/3.06 The YP-10M Reduction gear system is a Constant-mesh spur gear, with a Mechanical wet type single disk clutch and the KH-18 Reduction gear system is a Constant-mesh helical gear, with a Mechanical wet type multi disk clutch. I have no idea what all of this means but I hope that this may help. Frank Noragon S/V: Cool Change C&C 38LF, s/n: 001 Rose City Yacht Club Portland, Oregon ___ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated!
Re: Stus-List Transmission ratio for LF38
According to my records...my transmission is 1-1 and the vdrive is 2-1. ___ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated!
Re: Stus-List Transmission ratio for LF38
I believe my transmission is 2.14:1. Not 100% sure, but when I had it rebuilt two years ago I had someone check it and that's what they said it was. Also I had considered replacement and they had 2.7:1's in stock but no 2.14:1. Just curious where are you getting your new transmission? I had the impression they were hard to find. Are you still in Fiji? I found your blog but no updates since 2014 - would love to read if you decide to take it back up. I have a 3 blade 18" Autoprop. It provides good power, but we do lose significant speed motoring upwind in 15 kts or more. It sounds like you might be underprop'd a bit with the 2-blade 16". My mechanic when I had the transmission rebuilt called the Autoprop transmission killers. He was more a fan of MaxProp's and said they're more common. Not sure if the "transmission killer" bit is true or not, but we found a prior owner had misinstalled the transmission with a mismatched shaft coupler (different size inner ring), so hoping that was the cause. -Patrick 1984 LF 38 Seattle, WA On Sun, Sep 3, 2017 at 3:51 PM, wrote: > > -- Forwarded message -- > From: Anthony Mitchell > To: "cnc-list@cnc-list.com" > Cc: > Bcc: > Date: Mon, 4 Sep 2017 09:33:19 +1200 > Subject: Stus-List Transmission ratio for LF38 > Unfortunately our ZF 15 MIV transmission needs replacement. The current > gearbox has a 2.13:1 gear ration and I believe the gearbox has been > replaced in the past. The owners manual for the LF38 says the ration should > be 2.83:1. Our prop is a two blade 16" x 13" x 1-1/8" RH which more closely > matches the specs for the LF35. > > Can any LF owners confirm their transmission ratio. I'm not certain that > our gearbox is correct, and if we're purchasing a new one, it will be good > to get it back to standard. > We get along OK with the current setup but the performance is not > outstanding to windward. > > Tony Mitchell > SV Irish Melody, > 1983 LF38 #150 > Vuda, Fiji > > ___ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated!
Stus-List Transmission ratio for LF38
Unfortunately our ZF 15 MIV transmission needs replacement. The current gearbox has a 2.13:1 gear ration and I believe the gearbox has been replaced in the past. The owners manual for the LF38 says the ration should be 2.83:1. Our prop is a two blade 16" x 13" x 1-1/8" RH which more closely matches the specs for the LF35. Can any LF owners confirm their transmission ratio. I'm not certain that our gearbox is correct, and if we're purchasing a new one, it will be good to get it back to standard. We get along OK with the current setup but the performance is not outstanding to windward. Tony Mitchell SV Irish Melody, 1983 LF38 #150 Vuda, Fiji ___ This list is supported by the generous donations of our members. If you wish to make a contribution to offset our costs, please go to: https://www.paypal.me/stumurray All Contributions are greatly appreciated!
