Generator Nut

[John P.]

My generator nut and lock washer turned up missing. It seems to be a strange size. Where can I get a replacement?

 

[R Geiger]

(quoted from post at 07:11:30 10/12/11) My generator nut and lock washer turned up missing. It seems to be a strange size. Where can I get a replacement?

Might try a generator repair shop.

 

[Dell (WA)]

John........yep, weird size. 5/8-18 (NF) .......Dell

 

[TheOldHokie]

(quoted from post at 18:37:47 10/11/11) John........yep, weird size. 5/8-18 (NF) .......Dell

MPC says p/n 351124 -Nut (armature shaft to pulley) - .6689-20. That would be 17mm to match the shaft but with an imperial thread pitch - more than a little wierd. If you can't find one John call me and I'll whip one up.....

TOH

 

[John P.]

Oh I can see this is going to be fun.

 

[TheOldHokie]

(quoted from post at 19:01:51 10/11/11) Oh I can see this is going to be fun.

About 15 minutes work to cut that thread on a lathe.

TOH

 

[John P.]

Thanks for the inputs and the size. I found a set of 3 of them on eBay with the lock washers. It is lised as .669-20 for Delco-Remy, so I think it will work.

 

[John P.]

Since I need to drop off the generator for brushes and bearings I probably could have got one there.

 

[John P.]

Tried that, but it would not fit on the shaft.

 

[gahorN]

I'm a generator-nut. I much prefer them over alternators due to originality. But having said that.... my 9N came with an alternator so that's what I got.

Speaking of nuts.... did you hear about the psychiatric patient to walked into the psychologist's office wearing nothing but cellophane shorts?

The doctor said to him, "I can plainly see you're nuts!"

:lol: :lol: :lol:

 

[TheOldHokie]

(quoted from post at 19:25:31 10/11/11) Thanks for the inputs and the size. I found a set of 3 of them on eBay with the lock washers. It is lised as .669-20 for Delco-Remy, so I think it will work.

Yes - Google returns a lot of hits for ".669-20 nut". Seems it is still used on some alternators....

TOH

 

[Jock(OR)]

The 17mm is for the shaft to fit the standard metric ball bearing inner race. The 20 threads per inch is so the shaft could be threaded on an American lathe before the changover to metric. Ball bearings (and roller bearings) early on standardized on metric sizes, probably because so many were made in Sweden. It is somewhat rare to find a quality ball bearing in inch sizes, while the lower grade ones often are inch size.

I'll bet that the subcontractor for the generator shafts didn"t have metric threading capability, so they decided to use the 20tpi. It was more cost effective to buy special nuts than turn a shoulder on every shaft to accomodate a 5/8-20 nut.