Hardi Ranger 550 Instruction Book page 23

Pump with 6 splines/540 r.p.m.
The shaft must always have an overlap (A) of minimum 1/3 of the length.
Pump with 21 splines/1000 r.p.m.
The shaft must always have an overlap (A) of minimum 2/3 of the length.
4. The two parts are shortened equally. Use a saw, and file the profiles
afterwards to remove burrs.
5. Grease the profiles and assemble male and female parts again.
6. Fit the shaft to tractor P.T.O. and sprayer pump shaft.
ATTENTION! Female part marked with a tractor towards tractor!
7. Fit the chains to prevent the protection guards from rotating with
the shaft.
8. To ensure long life of the transmission shaft, try to avoid working
angles greater than 15°.
4 - Sprayer setup
4.3