Old Britts
Drifts used in building a Commando
by Fred Eaton

Last updated 10/31/05

Over the years I have made a number of drifts to remove and install bearings, bushings, oil seals and other like items. Since I am building a Commando from the frame up and documenting every step, I decided to label and dimension all the drifts that I use. Some day when I get my turning center, I may produce sets of drifts for sale and rent, until then if you have access to a lathe, you can make some of the drifts needed to build a Commando. Most people use a socket as a drift and you should also be able to find different sockets that fit the dimensions listed below. The advantage of a drift over a socket for inserting a seal or bearing is that the first step will center the drift on the seal or bearing. If you do use a socket, make sure your socket is centered and will not hang up on the bore.

This list is not complete and will grow as I build this Commando.

drift dimensions
The above diagram shows what I mean by First Step & Second Step. A few drifts have a third step for convenience, but if the third step is important, it will be listed in the Drift Use section. Please note that for installing a bearing, the First Step will fit into the inner race of the bearing and there should be a recess on the face of the Second Step, so that step only presses against the outer race and does not touch the inner race.

First Step Second Step Wheels
Drift No. Diameter Length Diameter Length Drift Use
CD-0001 0.662" 4.750" 1.500" 1.200" To install wheel bearings (04-0100 & 06-7688). See Wheel Bearing Upgrade Instructions for a picture and description of use.
CD-0002 0.555" 0.200" 0.680" 1.625" To remove and install front brake drum expander bushings (06-7750).

To remove the rear hub bearing spacers (06-2069 and 06-7701). See Wheel Bearing Upgrade Instructions for a picture and description of use.
CD-0003 0.370" 0.070" 0.750" 1.000" To rivet the front drum brake short pivot pin (063273). See Drum Brake Performance Kit for a picture and description of use. This drift's first step is .370" for about .010" and then tapers out to .480".
CD-0004 0.660" 0.950" 0.750" 0.800" To install front drum brake spindle bushing. See Commando Front Drum Upgrade Information for a picture of this bushing.
CD-0005 0.650" 0.250" 0.750" 1.750" To remove the drive side bearing, MK3 rear hub, by pressing out the bearing spacer from the disc side.
CD-0006 0.660" 0.450" 2.845" 0.850" To install the disc side bearing (06-5541), MK3 rear hub.

First Step Second Step Frame
Drift No. Diameter Length Diameter Length Drift Use
CD-0011 0.975" 0.425" 2.000" 0.800" To install the steering head bearings (06-7604).

First Step Second Step Gearbox
Drift No. Diameter Length Diameter Length Drift Use
CD-0001 0.662" 4.750" 1.500" 1.200" To install the layshaft bearing (06-7710 & 04-0100) in the gearbox shell.
CD-0021 1.720" 0.125" 2.070" 1.000" To install the mainshaft oil seal (04-0132) in the gearbox shell.
CD-0022 1.240" 0.500" 2.430" 1.500" To install the sleeve gear bearing (04-0098) in the gearbox shell.
CD-0023 0.600" 0.350" 1.500" 1.500" To install the right hand mainshaft bearing (04-0099) in the gearbox inner case.
CD-0024 0.683" 0.850" 0.750" 1.000" To remove and install the 1st gear layshaft bushing (04-0046) in the layshaft 1st gear.
CD-0025 1.000" 0.125" 1.400" 1.000" To install the kickstart shaft oil seal (06-6145) in the MK3 gearbox outer cover.
CD-0026 0.550" 0.350" 0.605" 1.000" To install the gearshift outer bushing (06-5184) in the MK3 gearbox outer cover.
CD-0027 0.810" 0.600" 0.900" 2.700" To remove and install the sleeve gear bushings (04-0062).

First Step Second Step Engine
Drift No. Diameter Length Diameter Length Drift Use
CD-0041 0.846" 8.250" 1.000" 1.600" To remove and install camshaft bushings (06-2600, 06-3020, 06-5425 & 065428).

First Step Second Step Primary Cases
Drift No. Diameter Length Diameter Length Drift Use
CD-0051 0.680" 0.950" 0.775" 1.000" To remove and install the MK3 outer primary shift shaft bushing (06-6189).

First Step Second Step Carburetors
Drift No. Diameter Length Diameter Length Drift Use
CD-0061 0.245" 0.250" 0.300" 0.250" Third step (Dia= 0.330, Len= 3.750).
Used to remove and install the spray tube in an Amal Carburetor.


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