MTFCA Forum

How much fore and aft slack is allowable in a 26-27 Model T generator? The gear seems to be tight on the shaft and the generator works normally, but I can move the shaft back and forth about 3/32".

I believe the generator has two ball bearings. For the shaft to be moving in and out either the bearings are loose on the shaft or loose in the housings. Otherwise, the bearings themselves must be on the way out.

I could be wrong.
Allan from down under.

I read the service manual and found no reference to making any adjustment to the bearings. The gear comes very close to the timing cover when moved forward. Doesn't look right to me. The commutator looks normal and the bearings do not seem to have radial play, but I haven't taken the generator off the car yet.

Shim the rear bearing forward in its housing.

Thank you, Scott. I'll give that a try.

TXGOAT2 wrote: ↑

Fri Oct 15, 2021 8:41 pm

Thank you, Scott. I'll give that a try.

Put an extra felt front washer between the bearing & the rear cover to take up the extra space..

The Coilman put me on to a 'finger disc spring' made specifically for this purpose, it goes inside the endcap and presses against the bearing with moderate spring pressure taking up the endplay. Because it is a spring, it accomodates thermal expansions/contractions without binding or getting loose, and it won't get chewed up or attract dirt like a piece of felt. If you own a Coilman generater rebuild, I bet you own this part. It is McMaster Karr p/n 9717k65, jb https://www.mcmaster.com/catalog/9717k65

James that’s a great solution. I’ll give that a try.

It was a perfect fit in the generator I rebuilt. I wish the vendors would carry those springs as individual sale items. jb (And I wish mtfca would rewrite the electrical guidebook, removing the suggestion to bash in the generator endplate with a hammer to take up this endplay, and maybe suggest using a finger spring washer instead!)

The generator needs some end play, and the spring washer is an ideal solution, whether used alone or with some shimming in the case of worn parts. It looks as though the large bearing is supposed to be a light press fit and the small bearing is supposed to be a very light press fit. Either my bearing(s) are loose or the large bearing is too loose in the end frame.

Pat: Likely loose bearing on gear end of shaft. I replaced both brgs with sealed units and used green penetrating loctite on the gear end brg/shaft. I like the notion of sealed brg on gear end to keep oil out of gen housing, tho I still used the oil slinger ring. best, jb