Auto Prop Rebuild

Mark Erdos

(I took the liberty of changing the subject line)



Also, they have a great series of on-line videos that show how to do this:


Although, I haven’t found the one yet that shows how to put it all back together.



With best regards,





Sailing Vessel - Cream Puff - SM2K - #275

Currently cruising - Grenada


From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Sunday, August 27, 2017 4:04 PM
To: amelyachtowners@...
Subject: RE: [Amel Yacht Owners] Rpm




Replacing the bearings on the Autoprop is easy but time consuming.

However you are a short drive from AB marine in Newport. They are the Autoprop dealers and are very helpful. I am sure they could rebuild your prop in a few days. Otherwise they can sell you the parts and rent you the tools.

Fair Winds


Kimberlite Amel Super Maramu #376



From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Sunday, August 27, 2017 11:17 AM
To: amelyachtowners@...
Subject: Re: [Amel Yacht Owners] Rpm





When you service the propeller, exactly what is done? Is it new bearings? Can one fix that one self or do I need to send it away? We have clean bottom and newly Velox on the propeller, and Greased the propeller but it  only reach 2600 rev on our TMD 22. Before we reached 2800, I thought it might be the turbo being slow and need cleaning again, or the injectors. We hade the turbo serviced 1000 h ago, do not know how often one should service it, we try to now and then runthe engine hard for 20 to 30 minutes to clean out some carbon dust.

Paul on SY Kerpa SM#259 currently in Bristol RI

eric freedman


Here are the instructions for the autoprop. Takes a bot 3 hours due to the difficulty inremoving the split bearing from the blade.

Fair Winds


SM 376 Kimberlite

H6 Roller Bearing General Instructions


Your Autoprop is supplied assembled, tested, balanced and ready to fit to your yacht. 

Observing the following instructions will ensure a correct installation and trouble free service for a long time. Do not grease your propeller during installation.




Before fitting your new Autoprop ensure that the cutlass bearing is not worn.  A worn cutlass bearing will not be suitable for any propeller.  If it is worn replace it with a good quality bearing assembly with a brass shell.


  1. After removing the old propeller check that the shaft taper, key and thread are undamaged.


  1. Try the new shaft nut (#11) on the thread.


  1. Check that the key will slide through the keyway in the propeller hub. Clean and dry the taper on the shaft.


  1. Without the key in the shaft push the Autoprop onto the shaft firmly.  Mark the shaft at the fwd end of the propeller hub.  Now remove the Autoprop and install the key into the shaft.


  1. Re-install the Autoprop making sure that the fwd end of the hub comes to the mark you have made on the shaft previously.  If it does continue with the installation.
  2. If not then you will remove the Autoprop and file the key until you can push the Autoprop onto the shaft to your mark.  This is now showing that the propeller hub is matching the shaft taper correctly.


  1. Tighten the shaft nut (#11) to the shaft with a socket spanner (0.875).


  1. Install and tighten the shaft nut locking screw (#10) into the shaft nut.  It may be necessary to dimple the nut if the locking screw does not match up with one of the flats on the shaft nut.


  1. Smear the shaft nut locking screw (#10) with Loctite or other thread locking compound and retighten into the hub against the shaft nut.


  1. Replace the zinc anode (#12) with the nylon screws.  Do not over tighten.


  1. The Autoprop is now ready to use.  There is no need to grease the propeller as it has been done at the factory prior to shipping to you.




Removal of your Autoprop:


Autoprop makes and sells an Autoprop specific propeller puller.  However most three legged prop pullers will work with the Autoprop.


  1. Remove the zinc anode from the aft end of the propeller.


  1. Undo the shaft nut locking bolt … at least until it is clear of the shaft nut.


  1. Unscrew the shaft nut from the shaft.


  1. Remove the propeller using either the three legged puller or the Autoprop puller. It is not correct to simply pound the fwd end of the hub with a hammer.


  1. If using the Autoprop puller, screw the plate onto the back of the propeller using the socket head metric screws provided into the holes for the zinc attachment.  Now thread in the large jacking bolt and tighten against the end of the shaft until the Autoprop comes loose from the taper.


  1. Tape the key to the shaft for safe keeping.  Keys are a part of the shafting and not a part of the propeller. 



Haulout Inspection and Cleaning:


  1. Whenever you haul the boat for bottom cleaning or other reasons … have the Autoprop pressure washed before it has a chance to dry out.


  1. This will remove any deposits, which, if left to dry will make the propeller feel sticky when rotated.


  1. After washing, rotate the blades by hand to ensure they are free moving.


  1. Next “rock” the blades back and forth to also check for free movement in this direction.


  1. If movement is felt at this time then refer to the Bearing Adjustment section as the tension on the bearings might well require attention.


  1. Prior to re-launching the boat power wash the propeller as this will remove any foreign particles which may have lodged in the race and bearing areas.  Boatyards can be dusty locations.


  1. Please refer to the Greasing your Autoprop section should you need to re-grease the bearings.


  1. It is recommended to re-grease your propeller if you plan to have the boat hauled out for a long period of time.



Greasing your Autoprop:


To re-grease your Autoprop it is not necessary remove the propeller or to remove the blades

Always use a good quality waterproof lithium grease.  In USA we recommend

CRC # SL3110 .. generally found at an auto parts store like NAPA.


  1. Locate the grease channel screws (#7).  There will be two per blade … one at the side of the blade and one in the centre. Note that there are “O” rings fitted to each screw.


  1. Remove the 5mm pan head screws … two of them per blade, using an allen key.


  1. Fit the grease nipple (TRI-0168 supplied with each propeller) into the grease channel (#7) and connect to the grease gun.


  1. Pump the grease into the blade until you have forced the older grease out of the other hole (#7).


  1. During the procedure rotate the blade back and forth so as to get new grease around the bearings.


  1. When new clean grease exits the second hole in the blade you are finished.


  1. Remove the grease nipple.  Clean any excess grease from the blades and replace both of the channel screws (#7) into each blade.


  1. Proceed with the other two blades and you will be complete.



Autoprop Maintenance:


Your new Autoprop is fitted with greasing channels and screws in each blade.  It is not necessary to remove blades to re-grease the propeller.  It cannot be done under water, but should be done during a routine haul out and bottom cleaning.

It is recommended to re-grease every year if possible but at least every two years.


The Autoprop needs good protection from electrolytic and chemical corrosion. Ensure that you replace the zinc anode (#12) each year.  For extra protection it is advisable to fit a shaft zinc or shaft bushes, as the Autoprop zinc will only protect the propeller.


Eventually the Autoprop bearings will need replacing.  This is a straight forward  procedure and is covered in the kit when ever a bearing replacement is requested.

To order a bearing kit simply contact your Autoprop dealer and have the serial number (#serial number) at hand.



eric freedman

Kimberlite was  not coming up to speed. even though I dove on the prop to make sure it was clean and the blades moved smoothly without any wiggle I decided to rebuild the prop. The increase in RPM was dramatic after the rebuild..

The prop is a finely tuned device with very tight tolerances and a slight amount of wear will be obvious in the loss of rpm even though everything seems fine no wiggle and play in the blades.

The instructions to re install the bearings etc come with the prop rebuild kit.

It is a lot easier to re assemble that dis assemble. A torque wrench comes in handy if you want to get the install perfect. It is quite easy. The only thing that needs attention is the bending down of the retaining tabs.

I don't know how to add a drawing to this note. The drawing is quite detailed. Just make sure to grease all the bearings before installing. The people in Newport were very helpful.

Fair Winds,