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4788 Davit Rotation Stuck

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    4788 Davit Rotation Stuck

    I'm just getting around to the davit on this recently purchased 1999 4788 and find that I cannot push the davit arm in any direction. I raised the arm and it seems to be "locked" from rotating and I find no release. If it was frozen due to lack of use, I would think there would be some movement instead of it hitting a "hard stop" both directions. I have no OEM manual and there are no labels.

    Any info is appreciated.

    Craig and Karen aboard Rahn de Vous
    Last edited by Jim_Gandee; 06-14-2018, 10:12 AM.

    #2
    These davits utilize synthetic bearing sleeves made of 'nylocron' which will swell when petroleum based lubricants are introduced.

    In many cases the davits would get a little 'tight' and then an unsuspecting owner would lube the davit with products such as WD-40 or the like which would immediately make them much worse until they 'locked' in place.

    We have a procedure written up (pdf) on how to disassemble, clearance, and reassemble the davit with pics but it is too large for posting.

    If you want a copy please PM us with an e-mail address or state your e-mail on this post.

    Hope this helps
    Northport NY

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      #3
      Please the information on the davit repair, replace etc. The one on our 4588 sounding and looking bad. Thanks Rich rich2452@frontier.com

      Comment


        #4
        rich2452 wrote:
        Please the information on the davit repair, replace etc. The one on our 4588 sounding and looking bad. Thanks Rich rich2452@frontier.com
        The 45 and 47 davits are totally different.
        Started boating 1965
        Bayliners owned: 26 Victoria, 28 Bounty, 32, 38, and 47 since 1996

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          #5
          Over the winter, our 47 davit gets kinda stuck in the mud so to speak. Once I had to use a sail boat down haul tied to the dock cleat to get it moving and it has been sorta acceptable since. Whenever I need to move it, I use the dingy as lever to add length to the moment arm to start it moving. Just trying to move it alone is more difficult but easier using a longer moment arm. Just saying you should try harder to break it free and see what happens. The procedure to fix the bearing surface is not an easy task and you may get good use for while by just breaking it free. It is easier to break if with less down load. Make sure it is up as high as it goes and move the large elevation pin to the highest position.
          Started boating 1965
          Bayliners owned: 26 Victoria, 28 Bounty, 32, 38, and 47 since 1996

          Comment


            #6
            Thanks - I'll give it a try.

            Comment


              #7
              "The 45 and 47 davits are totally different."

              Perfect answer - they share zero parts and the designs are totally different.
              Northport NY

              Comment


                #8
                I tied a line on the end of the arm and used the added leverage to pull the davit around.

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                  #9
                  Can I get a copy of the 4788 davit pdf? I am not sure what PM means. thanks.

                  Comment


                    #10
                    smitty477 wrote:
                    "The 45 and 47 davits are totally different."

                    Perfect answer - they share zero parts and the designs are totally different.
                    With the exception of the bearing material that will swell if you use petroleum products on it.
                    Patrick and Patti
                    4588 Pilothouse 1991
                    12ft Endeavor RIB 2013
                    M/V "Paloma"
                    MMSI # 338142921

                    Comment


                      #11
                      Craig,

                      +100 on what smitty said. The davit on my 1997 4788 was extremely difficult to swing. It took three large guys to move it, and that isn't good. The PDF file was a great help to understand how the davit works and how to disassemble it. I assisted my favorite mechanic and his helper as they took my davit apart. In my case an earlier "repair" by a well-known company had included embedding two screws into the bearings and then lubing them on a subsequent visit with a petroleum-based lubricant that just damaged the whole works.

                      My mechanic took everything apart and made two new bearings, measured, cut and fitted perfectly. He added two zerk fittings for ease of future lubrication (with SuperLube, a synthetic lubricant). We reassembled everything and now the davit works like a dream. My wife and I can swing the dinghy on and off the boat without any outside assistance.

                      As noted in the PDF, this is a two or three person job. The davit arm is extremely heavy and the helper, a srong young guy, was sweating by the time the bolts were removed and we could lift the davit arm off. In addition if the bearings have been damaged you may need to find someone to craft new ones which will require synthetic material, a lathe, and accurate measurements. In my case the mechanic's shop was fifty yards from the boat and it required three trial fittings before everything was perfect. But now we are good to go! Good luck with your repairs.

                      Comment


                        #12
                        hollieanna wrote:
                        Can I get a copy of the 4788 davit pdf? I am not sure what PM means. thanks.
                        PM, private message, used a lot on these forums for 2 members to chat to each other.

                        Comment


                          #13
                          Just an update on my Davit. I bought the SuperLube from Harbor Freight (great stuff, ended up using it all over). There is a small 3/16" hole on the back of the davit vertical round base which opens to the area around the bearings. It looks like the intent was for a zerk fitting. I took the Superlube tube and starting squirting it in the hole. Then I would move the davit to spread the superlube inside. Kept repeating until I almost used the whole tube. Now my davit works better then it ever has and I avoided the hassle of removal and replacement. Everyone should give this a try before more drastic measures. Best $6 I ever spent. Sorry for no pictures of the hole, not at the boat right now. P.S. Hollie Anna is now on the hard for sale at Bananabelt Boats in Anacortes, WA. Priced right. Time for us to move on, but it has been a great 10 years!

                          Comment


                            #14
                            "hollieanna" post=511238 wrote:
                            Just an update on my Davit. I bought the SuperLube from Harbor Freight (great stuff, ended up using it all over). There is a small 3/16" hole on the back of the davit vertical round base which opens to the area around the bearings. It looks like the intent was for a zerk fitting. I took the Superlube tube and starting squirting it in the hole. Then I would move the davit to spread the superlube inside. Kept repeating until I almost used the whole tube. Now my davit works better then it ever has and I avoided the hassle of removal and replacement. Everyone should give this a try before more drastic measures. Best $6 I ever spent. Sorry for no pictures of the hole, not at the boat right now. P.S. Hollie Anna is now on the hard for sale at Bananabelt Boats in Anacortes, WA. Priced right. Time for us to move on, but it has been a great 10 years!
                            A marina friend a few years ago helped me drill and tap a zerk fitting in the same spot on our davit and I used Super Lube with great results as well.
                            1994 4788

                            Comment


                              #15
                              Hello,

                              After many years of never using my Davit, I went to use it earlier this month and it was seized. I put it in the upright position and with all my weight hit it with my shoulder. It would move a few inches at a time but was in no way good to go for a 675# dingy.

                              I tried the quick fix of drilling , tapping and installing two Zerk fittings, then greasing it with a synthetic grease but only had mild success.

                              Armed with Smitty 477's excellent step by step I disassembled it. READ it from end to end and all your questions will be answered

                              Point one,

                              I was alone and have heavy duty deck chairs on the bridge . I was able to place the arm of the davit on the arm rest of those SS deck chairs protected with old towels and did not have to lift anything 100%...only pivot. NOTE this was at dissasembly....when I reassembled I had my Admiral put in the pivot pin as I had to wiggle the davit arm to get proper allingment as it sat on the arms of my deck chair.

                              Point two,

                              My swivel assembly was so jammed I felt I was hitting against solid material as I tried to drive a wedge in to lift it a little. I thought it over an got two small bottle Jacks and some wood from the yard to act as shims and weight distributors.

                              I jacked each up easily from opposite sides and it came up extremely easily, no sweat and easily controllable.



                              Point Three,

                              As noted in Smitty's instructions there are two plastic/synthetic bearings . A lower one and an upper one. ON MY 2001 4788 the only bearing that was seizing was the lower one or the one near the deck. The upper one worked perfectly. I found this out by removing the lower one ( if you do this remove the small cotter pin that keeps the bearing in place) and then putting the svivel tube assy back together and observed the perfect smooth action when rotating

                              I only had to give some clearence to the ID of the lower plastic/synthetic bearing and then the unit worked fine.

                              I did not have Smitty's patience or wish to go to my Dads 20 miles away so I just used my small 4'' fein hand grinder with a flap disk and opened up the inside a little at a time. The lathe turning gives a nicer tighter finish but mine works just fine.

                              .................................................. .........

                              It worked for me and the Captain Morgan Spicy tasted better at happy hour when I was easily able to raise my 675# dingy up to my upper deck at the end of the day for the first time.

                              Hope this gives you some ideas,

                              Best Regards,

                              Pete

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