Thunderbolt Bearings

[NKTBOLT]

Hello everyone! So, im currently in the process of restoring my Thunderbolt 1000 Single phase B series siren, but need to know the correct bearings and brushes to get! Does anyone know the bearing and brush numbers, or could send a link? Thanks, Nicholas K

[Stormsetter4]

The earlier models used 87502 bearings, and the later models used 6202 bearings. You can use a 6202 in place of a 87502, but you will need to use a washer/spacer to fill the gap between the bearing and part of the shaft. The 6202 is also substantially cheaper and easier to find.

You'll want a double-sealed standard bearing.

6202

87502

You can order the brushes directly from Federal Signal, they are part #8247A020. Those will work for both the motor and collector ring assembly. When you first run the motor with the new brushes in it, pitch fluctuations are normal. The brushes are just being seated.

Hope this helps.

[CDV777-1]

When you take your chopper motor apart the numbers will be on the bearings.
I always put what was in there originally. They will be either one of the numbers stormsetter listed.
Thanks for mentioning the spacer stormsetter. I thought I was the only person who would go to the trouble to do that.