1100544 alternator shaft thread

[Tom L.]

I managed to booger up the threads on my dated alternator and need to clean up the threads. Anyone know what size die or chaser I need for this? Thanks!!

[Gary B.]

Re: 1100544 alternator shaft thread

The alternator I have here is 18-threads per inch. It measure 0.652 diameter and a 5/8"-18 tap will not screw over it. 5/8"-0.625, so it must be a special nut. If you have a thread file, use the 18- TPI to clean up the threads.
Gary B

[Joe L.]

Re: 1100544 alternator shaft thread

I managed to booger up the threads on my dated alternator and need to clean up the threads. Anyone know what size die or chaser I need for this? Thanks!!

Tom------


5/8-20 is the thread size.

[Harmon C.]

Re: 1100544 alternator shaft thread

Use a shaft from another alternator and your case with the numbers if you can't fix it.

[Joe L.]

Re: 1100544 alternator shaft thread

Use a shaft from another alternator and your case with the numbers if you can't fix it.

Lyle------


The rotor/shaft assembly from another alternator can be used as long as it's from an 10SI series alternator of 42 to 63 amp output.

One could also obtain an NOS rotor/shaft assembly and use it. The GM part is discontinued but can be found NOS or aftermarket.

As a matter of fact, using NOS internal parts and original case halves, one can build up what is, functionally, a brand new alternator with original case "numbers" and configuration----the best of both worlds.

[Tom L.]

Re: 1100544 alternator shaft thread

Thanks for the replies. I sourced a file and was able to take care of the problem last night. A not screws on by hand just fine now. Was real glad it worked out. just got the alternator back from being restored and din't want to have another armature sent out to be restored.

So I don't screw myself again, what would be a proper torque for this nut? Thanks!

[Dick W.]

Re: 1100544 alternator shaft thread

Lyle------


The rotor/shaft assembly from another alternator can be used as long as it's from an 10SI series alternator of 42 to 63 amp output.

One could also obtain an NOS rotor/shaft assembly and use it. The GM part is discontinued but can be found NOS or aftermarket.

As a matter of fact, using NOS internal parts and original case halves, one can build up what is, functionally, a brand new alternator with original case "numbers" and configuration----the best of both worlds.

It is also easy to make a 100 amp alternator out of.

[Joe L.]

Re: 1100544 alternator shaft thread

Thanks for the replies. I sourced a file and was able to take care of the problem last night. A not screws on by hand just fine now. Was real glad it worked out. just got the alternator back from being restored and din't want to have another armature sent out to be restored.

So I don't screw myself again, what would be a proper torque for this nut? Thanks!

Tom------


If you had to replace the rotor and you did it with an NOS piece, you would not have had to have it restored. It would be, by definition, "exactly original" (maybe even more original than the restored rotor).

Torque for the nut is 45 lb/ft.

[Tom L.]

Re: 1100544 alternator shaft thread

Thanks Joe!

[Richard G.]

Re: 1100544 alternator shaft thread

Sometimes you need a lathe or someone with one to help with the issue.
Most lathes will do the 18TPI, and it would just need to be set up and the machinist can clean up the threads.
Of course the rotor would have to be pulled to get it mounted in a lathe.
A file can work but if the nut wants to start crooked it's difficult to straighten out with a just a file.
The rotor can also be replaced and still keep the numbers matching case.
Best of luck with your project.

[Tom L.]

Re: 1100544 alternator shaft thread

As per Joe's comment it's 20 tpi, not 18. I successfully used a 20 tpi thread file and it worked out nicely.

[Joe L.]

Re: 1100544 alternator shaft thread

As per Joe's comment it's 20 tpi, not 18. I successfully used a 20 tpi thread file and it worked out nicely.

Tom------


Yes, it's a very uncommon thread size. Why, I have no idea. However, I'm sure there's a reason of some sort for it.