[Fot] TR 3/4 Southwick axle/bearing follow-up

[tr4racing at googlemail.com]

As a work around.

Put the race on a lathe and grind out radius to fit.

 

Cheers

Chris

 

From: Fot <fot-bounces at autox.team.net> On Behalf Of fubog1 via Fot
Sent: Tuesday, January 27, 2026 10:32 PM
To: FOT Triumph <fot at autox.team.net>
Subject: [Fot] TR 3/4 Southwick axle/bearing follow-up

 

Hi all- 

This is a follow-up to my recent post re TR-4/4 southwick axle specs & bearing fitting.

Apparently this was discussed around 5 years ago but I missed it, so I'm posting it again for those unaware of it.

The problem is that most of the replacement bearings don't fit, including the chicom Timkens.

The corner radius of the inner race is much smaller than the axle journal radius, where the inner race butts up against the axle shoulder, preventing the bearing race from pressing fully home.

This effectively weakens the axle since all of the stresses remain in the axle inside corner radius, instead of being distributed into the hub.

I measured a RW507ER Timken, National & unknown chicom bearing & all had a small radius.

The only bearing that actually fits is the 9507F “small ford” bearing from Moser, unknown manufacturer.

The photo below clearly shows that the Moser bearing inner race is relieved/clearanced out in the last ¼ inch or so before the radius, so the bearing presses fully home as intended.

BTW this is easily checked w/a feeler gauge, there should be NO clearance between the inner race & axle shoulder.

And many THANKS to those who responded to my post!

Glen Efinger

 

Moser on left

representative of the other 3 right

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