spud150 Posted October 3, 2014 Report Share Posted October 3, 2014 my prop is r/h what i need to know is can i run a l/h prop in reverse or does anyone have a r/h 17 x 14 with a 1 1/2 shaft for sale thanks Link to comment Share on other sites More sharing options...
RLWP Posted October 3, 2014 Report Share Posted October 3, 2014 More information needed. What gearbox do you have? The answer is likely to be no - the reverse gear arrangement in most gearboxes isn't designed for continuous use Richard Link to comment Share on other sites More sharing options...
spud150 Posted October 3, 2014 Author Report Share Posted October 3, 2014 hi its a prm 2.1 Link to comment Share on other sites More sharing options...
nebulae Posted October 3, 2014 Report Share Posted October 3, 2014 I believe that the PRM150 can be run either way. The only issue is that the fail safe facility ,where you can lock the gearbox in drive to get you home,only works with a right hand prop(unless you want to get home backwards,of course)I have been using a PRM150 with a left hand prop,for 2,200 hours with no problem.(I converted from Lister to Isuzu) 1 Link to comment Share on other sites More sharing options...
RLWP Posted October 3, 2014 Report Share Posted October 3, 2014 hi its a prm 2.1 There should be a plate on the gearbox somewhere. It would be handy to know the model number Richard Link to comment Share on other sites More sharing options...
spud150 Posted October 3, 2014 Author Report Share Posted October 3, 2014 There should be a plate on the gearbox somewhere. It would be handy to know the model number Richard ill have a look on sunday when i get over to the boat Link to comment Share on other sites More sharing options...
Southern Star Posted October 3, 2014 Report Share Posted October 3, 2014 I believe that the PRM150 can be run either way. The only issue is that the fail safe facility ,where you can lock the gearbox in drive to get you home,only works with a right hand prop(unless you want to get home backwards,of course)I have been using a PRM150 with a left hand prop,for 2,200 hours with no problem.(I converted from Lister to Isuzu) Hello, I never knew gearboxes had this get-home facility. Mine is a Hurth 150, does it have this ability, and if so how would I engage it? Link to comment Share on other sites More sharing options...
RLWP Posted October 3, 2014 Report Share Posted October 3, 2014 Hello, I never knew gearboxes had this get-home facility. Mine is a Hurth 150, does it have this ability, and if so how would I engage it? Afraid not. Some boxes are deigned to be in forward if something goes wrong. The Lister LH150 does this, the hydraulics pulling it out of forward and engaging reverse Some PRM boxes have this kind of facility - the PRM150 has an Allan key in a pocket behind the oil pump. Some of the bigger boxes have a blade on one of the covers that locks the box in forward when repositioned. On any of theses gearboxes, once you have used the 'get you home', the box needs to be rebuilt Richard Link to comment Share on other sites More sharing options...
Tony Brooks Posted October 3, 2014 Report Share Posted October 3, 2014 To add to what Richard said. The "get you home" device/design is only appropriate on hydraulic gearboxes where a hydraulic failure (low oil/pump fault etc.) would jamb the box in neutral so as the Hurth is a mechanical box (like the PRM 80 & 120) it does not need such a device. I am not sure about the TMP hydraulic box but I do not think it has a get you home device and I am sure the Velvetdrives do not. Link to comment Share on other sites More sharing options...
Southern Star Posted October 3, 2014 Report Share Posted October 3, 2014 Thanks fellas, I've learned something today, I'm fairly new to this so I'm sure the answer to lots of my questions will be obvious to those "in the know" but thanks for taking the time to explain it to me. Link to comment Share on other sites More sharing options...
David Mack Posted October 3, 2014 Report Share Posted October 3, 2014 And just to point out that the get-you-home facility is intended for sea-going craft where a gearbox failure could have serious consequences and an inability to go into neutral and reverse isn't an issue. Its not much help on the cut, particularly if there are locks between where your gearbox hydraulics fail and home. Link to comment Share on other sites More sharing options...
bizzard Posted October 3, 2014 Report Share Posted October 3, 2014 And just to point out that the get-you-home facility is intended for sea-going craft where a gearbox failure could have serious consequences and an inability to go into neutral and reverse isn't an issue. Its not much help on the cut, particularly if there are locks between where your gearbox hydraulics fail and home. I know what I'd rather do on a canal, use the forward gear get you home device on the gearbox rather than man haul my boat back home or leave it in a dodgy place. Surely its not much of a problem not to have an astern gear and neutral. You simply gauge your stopping distances, cut the engine in time and drift gently into locks arresting the boat forward movement with a turn of a stern rope around a handy bollard if necessary, restart the engine and drive out. Boatmanship all good practice. Link to comment Share on other sites More sharing options...
magpie patrick Posted October 4, 2014 Report Share Posted October 4, 2014 I know what I'd rather do on a canal, use the forward gear get you home device on the gearbox rather than man haul my boat back home or leave it in a dodgy place. Surely its not much of a problem not to have an astern gear and neutral. You simply gauge your stopping distances, cut the engine in time and drift gently into locks arresting the boat forward movement with a turn of a stern rope around a handy bollard if necessary, restart the engine and drive out. Boatmanship all good practice. Yup, Got Lutine from Fradley to Great haywood like this when the gear cable came off and I had no tools to get the control off and reattach. Worked fine for the five locks Not so good when I turned the corner onto Rugeley Aqueduct and found a boat mid channel on the aqueduct coming the other way though... Link to comment Share on other sites More sharing options...
John V Posted October 4, 2014 Report Share Posted October 4, 2014 On the subject of incorrect handed props. When I bought my yoghurt pot it's performance was pathetic (although fitted with a new diesel engine with tiny hours on the clock) It was obvious to me that it was incorrectly propped. On lifting out I discovered that not only was the prop the wrong size and pitch but was also the wrong hand, The connections in the Morse control had been swapped to compensate. The gearbox was a small Hurth and AFAIK this has a smaller thrust bearing in reverse than forward, fortunately no damage seems to have been caused img459 by mudlarker2, on Flickr Link to comment Share on other sites More sharing options...
RLWP Posted October 4, 2014 Report Share Posted October 4, 2014 On the subject of incorrect handed props. When I bought my yoghurt pot it's performance was pathetic (although fitted with a new diesel engine with tiny hours on the clock) It was obvious to me that it was incorrectly propped. On lifting out I discovered that not only was the prop the wrong size and pitch but was also the wrong hand, The connections in the Morse control had been swapped to compensate. The gearbox was a small Hurth and AFAIK this has a smaller thrust bearing in reverse than forward, fortunately no damage seems to have been caused Like many gearboxes, it has a different ratio in reverse Richard Link to comment Share on other sites More sharing options...
John V Posted October 4, 2014 Report Share Posted October 4, 2014 Like many gearboxes, it has a different ratio in reverse Richard Yes ...noticed that as well......knew pitch was wrong, guessed size was wrong but was actually shocked hand was wrong....I mean there are bodges and there are bodges! fancy installing a brand new engine and gearbox and not spending the extra hundred odd quid on a prop....unbelievable Link to comment Share on other sites More sharing options...
spud150 Posted October 7, 2014 Author Report Share Posted October 7, 2014 There should be a plate on the gearbox somewhere. It would be handy to know the model number Hi it's a prm 150 , nebulae says he has run his prm 150 backward for 2200 hours with no problems so I am guessing I should be ok till I find a 18x14 1 1/2 prop ,thanks Richard I believe that the PRM150 can be run either way. The only issue is that the fail safe facility ,where you can lock the gearbox in drive to get you home,only works with a right hand prop(unless you want to get home backwards,of course)I have been using a PRM150 with a left hand prop,for 2,200 hours with no problem.(I converted from Lister to Isuzu) Link to comment Share on other sites More sharing options...
Tony Brooks Posted October 8, 2014 Report Share Posted October 8, 2014 On the subject of incorrect handed props. When I bought my yoghurt pot it's performance was pathetic (although fitted with a new diesel engine with tiny hours on the clock) It was obvious to me that it was incorrectly propped. On lifting out I discovered that not only was the prop the wrong size and pitch but was also the wrong hand, The connections in the Morse control had been swapped to compensate. The gearbox was a small Hurth and AFAIK this has a smaller thrust bearing in reverse than forward, fortunately no damage seems to have been caused Although there may be an issue with the thrust bearing possibly the more serious problem on the mechanical boxes is the lubrication of the extra gear(s) needed to provide reverse. This is far more important on the old boxes using planet gears for reverse but can also be an issue on the more modern boxes with a single idler gear. This is small in comparison to the other gears so will spin fairly fast and only relies upon splash lubrication. Hydraulic boxes tend to use force fed lubrication so the lubrication is more assured. Link to comment Share on other sites More sharing options...
Featured Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now