Mounting on Saildrive
Mounting on SAILDRIVES over an industry standard SAE 16/32 17 tooth spline on 28 - 28.15 mm ø shaft.
First ensure that both internal and external splines are scrupulously clean.
While every effort is made to remove any burrs from the castings on the internal splines these can cause jamming when mounting and may need a wipe with a file as manufacturers spline specifications can differ by up to 0.15 or 0.006". The unit has been prefitted over a manufacturers spline and should slide easily onto the spline on the any model of Saildrive.
Check the ~10 mm thick collar with seal shield is on the shaft. (Yanmar # 196420-09250 Volvo # 851984 )
Remember if you are fitting to units that previously had cutters installed - then these would have required the removal of the guard collars designed to keep monofilament line off the bearings and accept the forward thrust of the propeller.
Check the GF PP nose cone is not binding on the zinc. Some units such as Lombardini come with collars and washers which must be mounted. All Saildrives require that the distance from the end of the spline to the face taking the thrust is exactly 3.000” or 76.20 mm. All Saildrive propellers then have bosses which are ~ 3.125” or 80.00 mm long to ensure they pull up tight on the thrust face before the M16 (M20 for Yanmar SD40 or SD50 Saildrives) nut starts to bind at the end of the thread.
Remove to expose ~ 80 % of the 2 x M8 locking grub screws at the rear of the unit. Coat all thread surfaces in Loctite™.
Apply Loctite™ to the M16 or M20 Attachment Nut --- All are Right Handed and tighten clockwise. The grade of Loctite™ is not critical - a blue medium strength is recommended.
Tighten the main attachment nut using the socket set - minus a socket.
DO NOT overtighten the nut which attaches to any standard ½ inch socket driver.
SAILDRIVE nuts should be tightened to a torque of ~ 40 ft-lbs or 55 Nm.
Screw the M8 lock screws into boss and tighten down securely now that the main attachment nut retaining the propeller is correctly locked in.
NB: A FAILURE TO TIGHTEN THESE TWO LOCKING SCREWS AND SECURE ALL THREADS WITH LOCTITE™ CAN LEAD TO THE LOSS OF THE ENTIRE PROPELLER UNIT OVER TIME ON A SAILDRIVE UNIT.
Saildrives post serial # 8650 have an additional M8 x 40 failsafe Right Hand Cap screw as used by Volvo that provides an additional level of locking security where the boss can never be tight on the parallel spline. The pitch differential between these two components provides the locking effect.
Finally apply Loctite™ then fit & torque the M8 Failsafe Screw that locates inside the square drive main nut recess. Again, a medium strength blue grade is recommeded.
This M8 Cap Screw should be tightened to ~ 5 ft-lbs or ~ 7 Nm.
We suggest a medium grade of Loctite™ to ensure subsequent ease of removal.
NB: Saildrive nuts and their locking screws should be checked and re-tightened at each haul out as Splines by their nature may fret slightly in use and could loosen the locking screws.