Cutless Propeller Shaft Bearings

Cutless Bearing Clearances

and Replacement Guidelines

When do I replace my cutless bearing?

Water Flow Rate Desired for Cutless Bearing: 2 GPM Per Inch of Shaft Diameter.

Replace Cutless Propeller Shaft Bearing:

When 1/2 of water V groove has been worn away.

Another indicator is when shaft feels loose in the bearing.

Bearings Tolerances:

The following are the standards established by the US Navy, according to BuShips plan number 810-1385664:

How to Install and Modify a Cutless Propeller Shaft Bearing

Hole Drilling Diagram for Flange on Flanged Propeller Bearings

3/4"

thru

1 3/8"

+.003

to

+.008

1 7/16"

thru

1 7/8"

+.004

to

+.010

2"

thru

2 3/8"

+.006

to

+.012

2 1/2"

thru

3"

+.007

to

+.014

3 1/8"

thru

3 3/4"

+.008

to

+.015

3 7/8"

thru

4 1/4"

+.010

to

+.017

4 3/8"

thru

4 7/8"

+.012

to

+.019

5"

thru

5 3/8"

+.015

to

+.023

5 1/2"

thru

5 7/8"

+.017

to

+.015

6"

thru

6 3/8"

+.020

to

+.029

6 1/2"

thru

6 7/8"

+.022

to

+.032

7"

thru

7 3/8"

+.024

to

+.034

7 1/2"

thru

7 3/8"

+.025

to

+.035

8"

thru

8 3/8"

+.027

to

+.037

8 1/2"

thru

8 7/8"

+.028

to

+.040

9"

thru

9 7/8"

+.030

to

+.042

10"

thru

10 7/8"

+.032

to

+.044

11"

thru

11 3/8"

+.034

to

+.048

11 1/2"

thru

12 3/4"

+.035

to

+.050

12 7/8"

thru

13 3/8"

+.037

to

+.052

13 1/2"

thru

14 1/2"

+.040

to

+.055

14 5/8"

thru

15"

+.042

to

+.058

1 1/4"

thru

2"

+.001

to

-.001

2"

thru

6"

+.002

to

-.001

6"

thru

7 1/2"

+.002

to

-.002

7 3/4"

thru

12"

+.005

to

-.005

12"

thru

16"

+.006

to

-.006

16"

thru

18"

+.008

to

-.008